1902.] NEW SPECIES OF EARTHWORMS. 209 



egg-sac. There is also an outgrowth of the ovarian sac into the 

 thick muscular walls of the oviduct, to form a cavity which is that 

 figured by Michaelsen in P. usindjaensis ', and which is therefore, 

 as I think, not the " Ovarialblase." This sac does not in its turn 

 communicate with either the receptaculum or the spermathecal 

 sac. I take it, however, to be — but this is purely theoretical — the 

 part of the originally single cavity which is in communication 

 with the spermathecal sac, the communication being cut off as the 

 latter grows. There is in addition another comparison that may 

 be made. In the case of the male organs the testicular sacs 

 (seminal reservoirs) are, as I have mentioned, the exact homo- 

 logues of the ovarian sacs, and both of them communicate with 

 each other. The long sperm-sacs arise as an outgrowth of the 

 septum, and their cavity communicates, not with the general 

 coelom. of segment xi., but with the interior of the seminal 

 reservoirs, which at that point are in contact with the posterior 

 wall of their segment. The orifice of comraunication is a minute 

 one, and immediately median of it is an ingrowth of the testicular 

 sac into the thickness of the very thick septum which divides 

 segments xi. and xii. The appearance of this prolongation of the 

 testicular sac is exactly that of the prolongation of the ovarian 

 sac just referred to ; and I cannot help considering that both 

 cavities are homologous. It would then possibly be a vestige of 

 the spermathecal apparatus appended to the female system, the 

 receptaculum of the lattei- being of course represented by the 

 sperm-sacs. I would reiterate, however, that this is merely a 

 suggestion. But that there is the actual likeness is a fact. 

 Dr. Michaelsen^ has figured a strand of "connective tissue," 

 attaching the thickened muscular walls of the oviduct to the 

 parietes of segment xiii. This structure exists in the worm 

 examined by myself, but it traverses the wall of the xiiith segment 

 and is attached to the posterior wail of segment xii. 



It is not, as it might be supposed to be, a vestige of the canal 

 connecting the cavity of the ovarian sac with that of the other 

 parts of the egg-conducting apj)aratus. It is simply a thickening 

 in the muscular attachments of the oviduct to the septa, com- 

 parable — I take it — to the " tendons " which tie the septa of this 

 and other earthworms to the parietes : the muscular and heavy 

 oviduct requires apparently some such fixed point. I may remark 

 that in the worm whose immature reproductive organs I have just 

 dealt with were germinal cells some way down the spermathecal 

 sac, thus showing that there must have been in this specimen a 

 communication between the ovarian sac and the spermathecal sac 

 such as exists in younger stages. A final point to which I desire 

 to draw attention is the fact that in the young stages the median 

 spermathecal sac has two lateral bi"anches, one on each side, into 

 which the oviducts open on the one part. In the adult worm, as 

 I have already mentioned, the spermathecal sac has no bi^anches, 



1 " Regenwiirmer," in ' Deutsch Ost-Afrika,' pi. i. fig. 19. 

 - Ihid. pi. ii. fig. 20 bis. 



Proc. Zool. Soc.~-1902, Yol. II. No. XIV. 14 



