98 Mr. E. Ray Lankester on the Organization 



sacculate bodies in the earthworm have the same origin as the 

 sheaths containing spennatospheres in the Ssennridae and 

 Naididaj. Hering pointed out that these sacculi were not true 

 testes, in opposition to D'Udekem, whose view I supported 

 in a paper on the earthwonn because I did not find the bodies 

 described as testes by Hering. I do not now feel sure wliat 

 the bodies called testes by him may be ; but I have found the 

 true testes in Lumhricus placed as in Tuhifex. In Lumhricus 

 there are at least two pairs. The true testes are clearly figured 

 in an immature Phreoryctes (a Lumbricoid) by Leydig. 



The view advanced by D'Udekem, that the penis in Tuhifex 

 is invaginated in the oviduct, is supported by Clapar^de. There 

 is really no evidence to support this view ; and, as stated by 

 both these authors, it is purely hj^jothetical, favoured chiefly 

 by the fact that no true oviduct has been found. The ripe ova 

 descend through the septa of several segments in a Tuhifex 

 rich in ova, and they thus recede to a very considerable dis- 

 tance from the male genital opening. Hence it is difficult to 

 comprehend how this can act as the orifice for the escape 

 of the ova. The manner of the deposition of the ova can only 

 be decided by observation, which is very difficidt in this 

 matter. 



The glandular organ attached to the pyriform part of the 

 male efferent duct has been called a seminal vesicle by Clapa- 

 r^de, though he admits that he has never seen zoosperms in 

 it. It is really, in all probability, a gland destined to secrete 

 a cement to aid in forming the spermatophores, which very- 

 remarkable bodies occur in all the Limicoljs apparently, but 

 were unknown to Clapar^de, since he mistook them, where he 

 did find them, for parasitic Opalinoid Infusoria, giving to 

 them the name Pachydermon. I have pre\nously given reasons 

 for regarding Claparede's various species of Pachydermon as 

 spermatophores (Quarterly Journal of Microscopical Science, 

 1870) ; but I have now watched their formation, and more 

 carefully ascertained their structm-e, so that the matter is be- 

 yond doubt. Claparede found species of Pachydermon in two 

 species of CliteUio and in Limnodrilus, and mentions one seen 

 by D'Udekem in Trdjifex. I have obtained these bodies in 

 great abundance in Ihihifex and in Limnodrilus^ and also in 

 Nais. They occur in the spermatic receptacles, and are emi- 

 nently characteristic of the different genera and species. They 

 are formed by the moulding of the spermatozoa with a cement- 

 ing substance in the long necks of the spermatic reservoirs. 

 A curious conical head is thus given to the spermatophore of 

 Tuhifex rivulorum^ con*esponding to the shape of the orifice 

 of the reservoir. The spermatophore of T. umheUifer has not 

 this head, but is pointed, tapering at either end. 



