256 DESCRIPTIONS OF EARTHWORMS. 



(fig. 6); these cells, which I suggest to be the male ger- 

 minal cells (spermatospores) differed from the female ger- 

 minal cells (oospores) by a less distinct nucleus. 



In the bodies, attached to the anterior septum in the 

 11th and 12th ring, I found the spermatospores in a more 

 advanced stage of development, showing the well-known 

 mulberry-shaped masses; mature spermatozoa have not 

 been observed. The organ itself has the same areolate 

 structure as we know to exist in the seminal vesicles of 

 other Lumbricina. I have no doubt therefore that the 

 lobed bodies in the 11th and 12th segment represent the 

 vesiculae seminales , originated by evagination and prolife- 

 ration of the dissepiment, as is the case in Lumhricus 

 and Criodrilus , according to the investigations of Bergh ^) 

 and Rosa *). 



In Ac. ungulatus in the 11th and 12th segment also 

 lobated glandular bodies are situated, much resembling 

 those of Ac. Schlegelii, and probably representing the 

 testes; they lie exactly in front of the ciliated roset- 

 tes of the sperm-ducts , at the internal side of the ne- 

 phridia. It was only by means of transverse sections that 

 I could find them out, for the septa in the genital region , 

 especially those of the 11th segment, are strongly thick- 

 ened and coalesced together. In all the specimens there 

 are two pairs of vesiculae seminales, quite separated from 

 each other. The anterior pair is attached to the anterior 

 side of the 10th septum, and situated in the 10th seg- 

 ment ; the posterior pair is fixed to the posterior side of 

 the 11th septum, lying thus in the 12th segment. 



From the foregoing considerations it maybe concluded, that 

 there exist in the species of Acanthodrilus real male genital 

 glands (testes), morphological aequivalents of the ovaria, 

 discharging their contents into the vesiculae seminales, 



1) Untersucli. iiber Bau und Entw. der Geschlechtsorg. d Regenwiirmer; Zeit- 

 8chr. f. Wissensch. Zoölogie. Bd. XLIV, 1886, p. 304, pi. XXI. 



2) Sn\ Criodrilus Lacuum , Memorie d. R. Accad. delle Scienze di Torino, 

 Ser. II, Vol. XXXVIII, 1887. 



Notes from the Leyden Museum , Vol. LX. 



