828 MR. F. E. BKDDAIID ON [NoV. 3, 



shape of these glands may be understood from the same drawing. 

 From transverse sections through the body, it could be seen that 

 these glands are closely adjacent to the terminal portion of the 

 vasa deferentia (Plate LII. fig. 9) just before they perforate the 

 mesentery. 



These glands possibly correspond to a pair of somewhat similar 

 glands described and figured by Perrier in Pontodrilus ' ; they are 

 also possibly to be compared to two glandular masses which I have 

 described myself in Megascole.v\ 



The position of these glands exactly corresponds to that of the 

 ovaries, attached as they are to the anterior mesentery of their 

 segment close to the middle ventral line ; their structure exactly 

 resembles that of the ovaries in those regions where the fully formed 

 ova are not found. A more positive proof that these glands are the 

 morphological equivalents of ovaria is the fact that in one example 

 of A. dissimilis, that I have studied, by means of transverse sections, 

 the posterior right-hand gland contained abundant ova, which 

 resembled in every detail the ova produced by the true ovaries which 

 lie in the succeeding segment. Beyond this single fact, which maj' 

 be an abnormality, but, like other abnormalities, serves as clue to a 

 morphological comparison, I have no evidence to offer as to the 

 function of these structures. 



The fact that there are frequently more than a single pair of testes 

 in Earthworms — there are two pairs for example in the present 

 species — renders it more probable still that the comparison which 

 I have instituted is a correct one. The multiplication of ovaries, as 

 well as of testes, naturally recalls the condition met with in herma- 

 phrodite Polychasta. These species of Jcanthodrilus appeRr, in fact, 

 to have preserved more completely than any other Earthworms, 

 the anatomy of which is known, the primitive condition of the gene- 

 rative organs. 



There is no Oligochsetous Annelid in which more than a single 

 pair of ovaries are known with certainty to occur ; Euclipidrilus, 

 according to Eisen '-, possesses three pairs of ovaries ; and in Chato- 

 gaster limncei, Lankester^ has described two pairs which are not 

 mature at the same time. Vejdovsky'', however, states that he has 

 never succeeded in finding the second pair in Ch. limnai, and is 

 of opinion that Eisen has mistaken other organs for the additional 

 pairs of ovaries in Euclipidrilus. 



The above suggestion as to the homologies of these anterior 

 glands is also borne out by their relations in the third of the three 

 species, viz. A. multiporus. It has already been mentioned that the 

 ovaries of this Acanthodrilus, instead of being attached to the anterior 

 wall of the 13th segment, are attached to its posterior wall in close 

 connection with the oviduct. There is a similar change in position of 

 the glandular bodies, which come to lie beneath the funnels of the 



' Loc. cit. pi. xiv. fig. 9, pi. xvii. fig. 37, and loc. cit. p. 504. 



- Koy. Soc. of Sciences, Upsala, tS8f. 



^ Quart. Jourii. Micr. Sci. vol. ix. new ser. 1869. 



■• System unci Morpliologie der Oligocluvten. Prag, 18S4, p. 145. 



