MISCELLANEOUS NOTES. 289 



P. boiticus finding the ants had forsaken it, adopted the new protective 

 device of sealing itself in the food-buds and that later the pillar -like 

 processes atrophied from continued disuse. 



F. C. ERASER, Capt., i.m.s. 

 HYDBRABA.D, SiND, February 1911. 



No. LIT.— SOME DISPUTED POINTS IN THE ANATOMY 

 OF A COMMON INDIAN EARTHWORM. 



In recent years it has become the custom for junior students of medicine 

 in India to practise the dissection of various animals. It is hoped that 

 by so doing they will foster a spirit of inquiry which perhaps lies dormant 

 at present. It is necessary that the student should have some written 

 guide to help him in such work, and it is essential that this gvxide should 

 be accurate so far as it goes, it should not invite the student to see 

 things which have no objective existence. I found it necessary to write 

 such a guide for the use of my students in Calcutta. Dr. A. Powell 

 had previously written a similar book mainly for the use of students 

 in Bombay ; this book was unknown to me until my own was in 

 the press. 



Among other animals a common species of earthworm, Pheretima posthuma, 

 was chosen by us both as a type for dissection. Although I did not con- 

 sult Dr. Powell's description, I received help from an earlier account of 

 the anatomy of this species, which was written by E. Perrier. (N. Arch. 

 Mus. Paris, Vol. VII.) 



In reviewing my book for this Society's Journal, Dr. Powell points out 

 certain discrepancies between our respective accounts of the structure of 

 FJieretima, assuming, naturally enough, that my account is inaccurate. I 

 do not, however, agree with him on the whole. 



The disputed points are as follows : — 



1. The distribution of the dorsal pores. Are they to be found in every 

 segment ? 



3. The nature of the male generative duct. Is it a single or a double 



tube on either side ? 

 3. The nature of those organs which I have called oesophageal glands. 



Are they excretory organs or have they some other function. 

 These points may be discussed in order ? 



In regard to the dorsal pores^ Dr. Powell is quite right. I had 

 overlooked the fact that they were not present in the i'lrst twelve 

 segments. 



In regard to the structure of the male generative ducts, I find that I 

 am right. If one of these tubes be excised and examined under the 

 87 



