D. Biswas, J.— Writ Appeal No. 181 of 1993 and Writ Appeal No. 264 of 1993 arising out of the judgment and order dated 8.9.1993 passed in Civil Rule No. 655 of 1993 are proposed to be disposed of by this common judgment. 2. Dr. Sanjib Kakati, the writ petitioner prayed for issue of a writ of Mandamus calling upon the respondents to finalise the gradation list and not to fill up the vacant posts of Assistant Professor in the Department of Medicine in three Medical Colleges in the State of Assam before finalisation of the gradation list 3. The learned Single Judge by the impugned judgment and order issued the following directions: '(i) The petitioner will be deemed to be a member of the service in the Department of Medicine of the Medical Colleges, Guwahati and he will be entitled to all the service benefits as are available to the other Registrars of Medicine and Resident Physicians. The petitioner would not be discriminated on the ground that he was originally appointed as Registrar of Medicine (Tropical and Infectious Disease). (ii) As on today I find that the Tropical and Infectious Disease is a part and parcel of the Department of Medicine and the petitioner is entitled to be treated as holding the service in the Department of Medicine. (iii) The petitioner will be entitled to count towards seniority, his period of service from 22.4.85/19.4.85 till his regularisation on 7.4.87. It is made clear that in determining/deciding the seniority the other similarly situated person in the Department should also be considered. It is further made clear that the law laid down regarding counting of seniority for the period of service under Regulation 3 (f), shall be kept confined only to the facts and circumstances of this ease and this decision will not be applied to open up a Pandora's Box to disturb/interfere with the seniority list already finalized fixed. (iv) The respondent Nos 2,3 along with other persons whose help/association may be necessary shall determine the seniority list of Registrar, Resident Physician, etc of the Department of Medicine of all the Medical Colleges, Assam within a period of 3 (three) months from today by considering all the objections, representations, which may be submitted by the persons concerned. (iv) The respondent Nos 2,3 along with other persons whose help/association may be necessary shall determine the seniority list of Registrar, Resident Physician, etc of the Department of Medicine of all the Medical Colleges, Assam within a period of 3 (three) months from today by considering all the objections, representations, which may be submitted by the persons concerned. If the authority feels necessary, it may notify all the members of the Medicine Department in the rank of Registrars etc to submit necessary objections, representations, etc by giving them time for 15 days to submit said representations. (v) No promotion, including ad hoc promotion, promotion under 4 (d) will be made to the post of Assistant Professor of Medicine without finalisation of the seniority list as indicated above, and thereafter only promotion will be made on seniority cum merit basis.” 4. Being aggrieved thereby, respondent No. 4 Dr. Anup Kumar Das and respondent No. 6 Dr. Sangitanjan Dutta preferred the appeals at hand on the ground that the writ petitioner Dr. Sanjib Kakati could not be given higher position in the inter se seniority list to the detriment of their respective position. 5. We have heard the learned counsel of all the parties. It emerges from their rival contentions that the controversy revolves around the sole question as to whether the period of service of an appointee under Regulation 3 (f) of the Assam Public Service Commission (Limitation of Functions) Regulation, 1951 could be counted for the purpose of seniority on final appointment or on regularisation of appointment. In order to appreciate this question in its proper perspective, it is necessary to examine the nature and spirit of appointment contemplated under Regulation 3 (f), which reads as follows : “3. In order to appreciate this question in its proper perspective, it is necessary to examine the nature and spirit of appointment contemplated under Regulation 3 (f), which reads as follows : “3. It shall not be necessary for the Commission to be consulted in matters relating to methods of recruitment to civil services and posts or the suitability of the candidates for such appointments, in the following cases, namely : … (f) when an appointment is to be made by direct recruitment to a temporary post created in a service if it is necessary in the public interest that the appointment should be made immediately and reference to the Commission would cause undue delay; provided that if the post has been sanctioned for, or is likely to last for more than four months, the Commission shall, as soon as possible, be consulted in all matters mentioned in sub-clause (3) of Article 320 of the Constitution. … 6. It would appear from the language employed in Regulation 3 (f) that the provisions therein contemplate immediate appointment to a temporary post for a period of four months only. Regulation 3 (f) obviously do not empower the State to make any appointment against any permanent post. The appointment made under Regulation 3 (f) is obviously non est and, therefore, the services rendered on appointment under Regulation 3 (f) cannot be counted for the purpose of j fixing the inter se seniority of the incumbent. The appointment, as the language employed suggest, being ad hoc in nature and de hors the rules, subsequent regularisation or substantive appointment will not make the incumbent eligible for seniority with effect from the date of his initial appointment. 7. In support of what is stated above, we may refer to some of the decisions of the Supreme Court. In The Direct Recruit Class II Engineering Officers e Association & others vs. State of Maharashtra & others, AIR 1990 SC 1607 , the Supreme Court was of the view that once an incumbent is appointed to a post according to rule, his seniority has to be counted from the date of his appointment and not from the date of his confirmation. The Supreme Court further held that where the initial appointment is only ad hoc and not according to rules and made as a stop gap arrangement, the officiation in such post cannot be taken into account for considering the seniority. This view is also available in the judgment of the Supreme Court in Union of India vs. SK Sharma AIR 1992 SC 1188 in which case the ratio laid down in DN Agarwal vs. State of Madhya Pradesh, AIR 1990 SC 1311 was followed. In V. Srinivisan Reddy vs. Govt of AP, AIR 1995 SC 586 , it was held that appointment/promotion must be made in accordance with rules and the direct recruit takes his seniority from the date on which he starts discharging the duty of the post borne in the cadre. According to the Supreme Court, a temporary appointee appointed de-hors the rules on ad hoc basis or to a fortuitous vacancy gets seniority from the date of regular appointment. In YH Pawar vs. State of Karnataka, (1996) 10 SCC 444 , the Supreme Court was of the opinion that when appointment was made on ad hoc basis without any competitive examination, such appointment although made prior to commencement of the recruitment rules are ad hoc and not regular appointment and that on subsequent regularisation of the appointment sometime after the coming into force of the recruitment rules, the appointee is entitled to seniority not from the date of initial appointment but from the date of regulari sation. In the State of UP & others vs. Dr. RK Tandon & others, (1995) 3 SCC 616 , reiterating the same view the Supreme Court held that all ad hoc appointments de hors the rule do not confer any right to pension or seniority, they acquire the rights only from the date of their regular appointment according to this rule. If, however, the initial appointments are according to rules though on ad hoc or temporary basis, the seniority then would be counted from the date of initial appointment. 8. If, however, the initial appointments are according to rules though on ad hoc or temporary basis, the seniority then would be counted from the date of initial appointment. 8. An attempt was made by the learned counsel relying on the judgment of the Supreme Court in SB Patwardhan & another vs. State of Maharashtra & others, AIR 1977 SC 2051 that in the absence of rules, the Executive Instructions contained in para 10 (ABP 51/63/1 dated 5.2.1954) will govern the subject as there is no recruitment rules and, as such, the appointees under Regulation 3 (f) are entitled to seniority from the date of their initial appointment as per provisions of the Executive Instructions contained in para 10 referred to above. Para 10.2 relied upon is quoted below : “10.2. Appointments made under Regulation 3 (a) and 3 (f) of the APSC (Limitations of Functions) Regulations and later regularised through the APSC: Normally the appointments made under these two Regulations should be regularised within the time limits specified in the Regulation itself. The seniority of the persons whose appointments have regularised should be determined as follows: (i) If the appointments of two persons are regularised earlier should be considered senior to the person whose appointment was regularised later. (ii) If the appointments of a number of persons are regularised on one batch, then the inter se seniority of these persons should be according to the merit list of APSC. Even if the APSC does not give any merit list, the appointing authority should request the APSC to indicate the order of preference of these persons. (iii) If the APSC does not give any merit list in spite of specific request from the appointing authority, then the following principles should be adopted : (a) At the time of appointment under Regulation the appointing authorities usually make appointments on the basis of the recommendations of a Departmental Selection Committee. The inter se seniority of persons who are appointed on the recommendations of such a Selection Committee should be fixed according to the order of preference indicated in the Selection Committee. The inter se seniority of persons who are appointed on the recommendations of such a Selection Committee should be fixed according to the order of preference indicated in the Selection Committee. (b) If there was no such Selection Committee, (or when the Selection Committee does not indicate any preference) then the date of the initial appointment under the Regulation should be the basis of fixing seniority, provided that at the time of initial appointment the persons concerned were fully qualified to hold the post and they join the posts within 15 days of their appointment. (But if a candidate is prevented from joining within this period, by circumstances of a public nature and beyond his control, the appointing authority may extend the period. In that case, the date of appointment will continue to govern seniority. If the period is not so extended, the date of joining will determine seniority). In all other cases, a reference should be made to the Appointing Department.” 9. It would appear that the instructions provide for regularisation of the appointees made under Regulation 3 (a) and 3 (f) of the Assam Public Service Commission (Limitations of Functions) Regulation, 1951 within the time limit a specified in the Regulation itself. We have carefully examined the provisions of the Regulation of 1951 and we do not find any provision enabling the authority to regularise the services of the 3 (f) appointees. The question for application of the Executive Instructions contained in the above circular will arise only when the appointments made under Regulation 3 (f) are regularised in accordance with the provisions of the rules, if any. But in the instant case there being no provision b incorporated in the Regulation to this effect, we are of the definite opinion that the conception of regularisation of the services of the appointees under Regulation 3 (f) is also de hors the.rules. We are of the further opinion that when a person is appointed under Regulation 3 (f), he has no option but to appear before the Commission for consideration of his case for recommendation when the post is advertised and in the event he is recommended and appointed, he will be entitled to all service benefits with effect from the date of such substantive appointment. The provisions contained in para 10.2 (b) has no application in cases where ad hoc appointments are made de-hors the rules under Regulation 3 (f) and regularised subsequently. Therefore, the services rendered by an incumbent to a post appointed under Regulation 3 (f) is not to be counted for the purpose of seniority. 10. In Shri M. Gogendra Singh & others vs. State of Manipur & others, (1992) 2 GLR 416 (1992 (1) GLJ 496) a Division Bench of this Court had the occasion to deal with almost a similar situation. In that case the decision of the Hon'ble Supreme Court in RK Kashyap, AIR 1989 SC 278 ; RN Ranjudappa vs. T. Thimmaih, AIR 1972 SC 1767 and BN Nagarjan vs. State of Karnataka, AIR 1979 SC 1676 were considered. The decision e rendered therein at para 23 of the judgment shows that ad hoc promotees or appointees were made eligible for regularisation from the date of their initial appointment or with retrospective effect in the following two circumstances : “(a) Where promotion is made after considering all the eligible candidates and/or after holding regular test and finding them qualified for promotion; and (b) Where the promotion or appointments are made de-hors the rules or by deliberate disregard to the quota rules but they are allowed to continue for many years uninterruptedly, after relaxing the rules to remove unjust and inequations results.” In addition we may also refer to another decision of the Division Bench of this Court rendered in Pranjit Kumar Das vs. State of Assam & others, (1995) 1 GLR 229 (1994 (2) GLJ 313). In that case the Court decided the rights and status of the ad hoc appointees in para 9,10 and 11 of the judgment. The decision rendered therein also augment the views expressed by us herein before. The observation of the Division Bench made in that case is reproduced below : “9. In that case the Court decided the rights and status of the ad hoc appointees in para 9,10 and 11 of the judgment. The decision rendered therein also augment the views expressed by us herein before. The observation of the Division Bench made in that case is reproduced below : “9. Reading proviso to sub-rule (1) of Rule 3 and clause © of sub-rule (2) of the said Rule 3, we are of the definite opinion that if the posts against which a person is appointed on ad hoc basis is likely to continue for more than 4 months, the Public Service Commission shall be consulted for making appointment on regular basis and for this purpose a review of all ad hoc appointment by the concerned department has to be made within a period of 4 months and if it appears that the post is likely to continue for more than 4 months, it is obligatory on the part of the department to send a proper requisition with draft advertisement to the Public Service Commission with a request to furnish the recommendation of the Commission for making appointment on regular basis. In other words, the above provision of the rule do not confer any right on the person who were appointed under the rules on ad hoc basis, to be regularised, but these rules cast a duty on the Public Service Commission on the basis of the draft advertisement issued by the department to send regular recommendation for making appointment on regular basis to the department. In other words, these rules of 1986 do not give any right to an appointee under these rules on ad hoc basis for consideration for regularisation in the post. But if the post is likely to continue tor more than 4 months duty is cast on the department to send an advertisement'to the Public Service Commission and thereafter make regular appointment on the recommendation of the Public Service Commission. 10. As after the Rules of 1986 were repealed and after that the appellants were appointed under Regulation 3 (f) of the Regulation of 1951, let us now consider whether the above Regulation confers any right on the appellants to claim regularisation on the basis of their appointment under Regulation 3 (f). 11. 10. As after the Rules of 1986 were repealed and after that the appellants were appointed under Regulation 3 (f) of the Regulation of 1951, let us now consider whether the above Regulation confers any right on the appellants to claim regularisation on the basis of their appointment under Regulation 3 (f). 11. This Regulation 3 (f) of the Regulation of 1951 came up for consideration by the Division Bench of this Court in Hemanta Kumar Pegu & others vs. State of Assam 1988 (1) GLJ 383 (1989) 1 GLR (NOC) 7. The Division Bench considered Regulation 3 (f) and held in paragraph 27 of the judgment that this Regulation does not provide a source of power for appointment, but only provides the mode of appointment that regularise does not cannot permanence. The contention that the persons who were appointed under Regulation 3 (f) can be regularised if they are otherwise qualified was not accepted by the Court and it was held that regularisation means making regular appointment by selection irrespective of the question whether the petitioners were already appointed under Regulation 3 (f) or not. The ratio laid down in the above decision in our opinion is the correct proposition of law and there is no reasons to take a different view. Therefore, in view of the above ratio, we are constraint to hold that merely because the appointments of the appellants were converted to appointment under Regulation 3 (f) of the Regulation of 1951, they cannot claim regularisation due to length of their service.” 11. In the instant case, although there is no recruitment rules prescribed, the appointments are required to be macte on the recommendation of the Public Service Commission. The Commission normally on request from the Govt advertise the posts and select candidates after interview. The State is required to make appointment from the merit list prepared by the Commission and the seniority of the incumbents are fixed in order of preference/merit indicated in the select list. That being the position, it would be difficult for us to accept the argument that an appointee under Regulation 3 (f) is entitled to seniority with effect from the date of his initial appointment and not from the date of his substantive appointment or regularisation in service. This conclusion is irresistible in view of various decisions of the Supreme Court and of this High Court referred to above. 12. This conclusion is irresistible in view of various decisions of the Supreme Court and of this High Court referred to above. 12. From the discussion above, it follows that the Govt have no powers to make appointment under Regulation 3 (f) to any substantive or permanent post and when appointments are made on ad hoc or stop gap basis de hors the rules, the appointees under Regulation 3(f) will not be entitled to seniority with effect from the date of initial appointment. However, the appointees under Regulation 3 (f) shall be entitled to seniority with effect from the date of substantive appointment on the recommendation of the Commission in accordance with their respective position in the merit list. 13. On the background of law, as emerges, we may now like to refer to the rival claims of the appellants and the respondent-petitioner. It would appear that Dr. Anup Kumar Das, appellant in the Writ Appeal No.181 of 1993 was recommended by the Public Service Commission on 4.12.86 for appointment as Registrar (Medicine) and he was appointed as such by the State Govt with effect from 24.4.87. Dr. Sanjib Kakati, the respondent-petitioner of Civil Rule No. 655 of 1993 was initially appointed under Regulation 3(f) as Registrar (Infectious Disease) on 19.4.85. The Commission recommended his case for regularisation/ regular appointment on 7.4.87 and vide order dated 7.5.87 he was appointed on regular basis with effect from 7.4.1987 ie the date when he was recommended by the Commission. Dr. Sangitanjan Dutta, appellant in Writ Appeal No. 264 of 1993 after being selected by a duly constituted Selection Committee was appointed as Registrar, Department of Medicine under Regulation 3 (f) for a period of four months vide notification of the Govt of Assam No. HCB 904/84/52 dated 18.1.85. After regular advertisement and interview, the Assam Public Service Commission vide letter dated 4.12.86 forwarded the list of candidates selected for the three posts of Registrars of Medicine, Medical Colleges of Assam in order of merit and Dr. Dutta was appointed as Registrar of Medicine vide order dated 7.10.87 on regular basis. The doctors named above, in view of the law discussed above, are only eligible for being treated as a member of the service for all purposes e including seniority from the date of their substantive appointment. Dr. Anup Kumar Das, a direct appointee, was appointed on 24.4.87 on regular basis. Dr. The doctors named above, in view of the law discussed above, are only eligible for being treated as a member of the service for all purposes e including seniority from the date of their substantive appointment. Dr. Anup Kumar Das, a direct appointee, was appointed on 24.4.87 on regular basis. Dr. Sanjib Kakati who was initially appointed under Regulation 3 (0 was appointed on regular basis with effect from 7.4.87. Dr. Sangitanjan Dutta, a 3 (f) appointee, was appointed with effect from 7.10.87 on regular basis. If we go by their date of appointment in substantive capacity, Dr. Sanjib Kakati appears to be the senior / to Dr. Anup Kumar Das. But in the impugned gradation list dated 25.1.88 (Annexure IV) Dr. Anup Kumar Das and other respondents have been shown senior to Dr. Sanjib Kakati. This gradation list showing Dr. Sanjib Kakati as junior to Dr. Anup Kumar Das and others is apparently contrary to the rights to the writ petitioner that emanates from the law as discussed above. The case of Dr. Sangitanjan Dutta stands on a different footing as he claims to have been 8 appointed under Regulation 3 (f) after selection by a duly constituted Selection Committee. Therefore, promotions made on the basis of this seniority list or that may be made would be detrimental to the rights of Dr. Kakati, The gradation list, therefore, needs correction. 14. However, the answer to the question whether the Registrars of different streams under the Department of Medicine belong to one and same cadre or not would be indicative of the necessity of combined or separate list for each of the streams. The learned Single Judge has discussed this question in details with reference to the documents on record and came to the finding that the different a streams/units under the Department of Medicine are not separate and watertight compartments, and the incumbents thereof are interchangeable. The learned Judge has endorsed the view that the Department of Medicine is a conglomeration of a number of recognized and accepted disciplines like- (i) Medicine (General) (ii) Tuberculosis and respiratory disease, (iii) Psychiatry, (iv) Paediatrics, (v) Endocrinology (vi) Neurology (vii) Cardiology (viii) Haematology (ix) Tropical and infectious disease 15. On this findings, the learned Single Judge also approved the claim of the petitioner that the discipline/stream of Tropical Infectious Disease is a cadre/ discipline under the Department of Medicine. On this findings, the learned Single Judge also approved the claim of the petitioner that the discipline/stream of Tropical Infectious Disease is a cadre/ discipline under the Department of Medicine. After a careful consideration of the respective pleadings and the documents on record, we are of the opinion that there being no order having been passed by the Govt to treat the different streams under the Department of Medicine as separate and independent and the incumbents holding posts in the said streams were freely transferred from one to the other, the unit of Infectious Disease which is treated as Unit No.VI under the Department of Medicine cannot be treated as of independent identity. The petitioner, therefore, is entitled to consideration for promotion to the next higher post of Assistant Professor (Medicine). This conclusion appears to be inevitable in view of the following special features that emerges on scrutiny of documents: (i) The basic qualification for appointment as Registrar/Resident Physician in all the Departments under the Department of Medicine is MBBS; (ii) There is no order/direction available in order to show that the different streams under the Department of Medicine are independent and the incumbent are not interchangeable; (iii) The Principal and Superintendent, Assam Medical College Hospital by the order dated 6.3.92 redefined the unit of the Tropical and Infectious Disease as Medical Unit No.VI under the Department of Medicine; (iv) By notification dated 7th May, 1987 (Annexure D) the petitioner, initially appointed as Registrar of Infectious Disease, was regularised in service as Registrar of Medicine (Infectious Disease); (v) The gradation lisi uated 7.9.1987 (Annexure IV) indicates that the branches, namely, Cardiology, Neurology, Medicine, Nephrology, Dermatology and Gastroenterology pertain to a common cadre; and (vi) The appointment letters, the advertisement issued by the Public Service Commission and the letters of recommendation nowhere indicate that the different streams under the Department of Medicine are of separate and independent entity. 16. By the order dated 11.11.1983, Dr. Jitendra Kumar Das was appointed as Additional Professor, Department of Medicine from the Department of Dermatology. Similarly the transfer and promotion of Dr. Krishna Barua made vide notification dated 30.11.91, posting of the petitioner vide notification dated 20.4.1990 as Registrar of Medicine, transfer of Dr. 16. By the order dated 11.11.1983, Dr. Jitendra Kumar Das was appointed as Additional Professor, Department of Medicine from the Department of Dermatology. Similarly the transfer and promotion of Dr. Krishna Barua made vide notification dated 30.11.91, posting of the petitioner vide notification dated 20.4.1990 as Registrar of Medicine, transfer of Dr. Dhiraj Das vide notification dated 27.4.1998 to the post of Resident Physician of Medicine (Infectious Disease) and various other orders of transfer and promotion referred to by the learned Single Judge in the impugned judgment lead to the irresistible conclusion that all a the streams referred to above belong to one and same cadre under the Department of Medicine. In the absence of rules or any Executive Instruction, this Court has no option but to take a decision from the surrounding circumstances, namely, the mode and manner of selection, the language employed in the appointment letters and subsequent administrative action in the matter of transfer and promotion. The circumstances in the case, as referred to, inspire us to agree with the learned Single Judge that the Department of Infectious Disease was one of the streams under the Department of Medicine and an incumbent to that post cannot be disentitled from being considered for promotion to the next higher post in the Department of Medicine. 17. It, therefore, follows that an appointee under Regulation 3 (f) is not entitled to seniority with effect from the date of his initial appointment. Such an appointee appointed on substantive basis and regularised thereafter on the recommendation of the Public Service Commission, is entitled to seniority from the date of his substantive appointment/regularisation only. It also follows that the post of Registrar of Infectious Disease is one of the posts under the Department of Medicine and the posts of Registrars in various streams mentioned herein before belong to one and same cadre. 18. We, therefore propose to dispose of the appeals with modification of the impugned judgment to the extent that the respondent-petitioner will be entitled to seniority with effect from the date of his regularisation/substantive appointment on 7.4.87 and not from the date of his appointment under Regulation 3(f). The respondent authority shall recast the gradation list as per law indicated above. e The other reliefs granted by the learned Single Judge on the facts and circumstances of the case require no interference. No costs.