204 MR. F. E. BEDDABD ON [June 17, 



seen to be cut across in various directions, and it is plain there- 

 fore that they lie irregularly within the cavity of the spermato- 

 phore-case. The heads of the spermatozoa, where they are 

 attached to the granular core, show a deep staining. The core 

 itself is unstained. These sperm-ropes have no connection with 

 the walls of the case which contains them. The latter hardly 

 shows a definite structure in its walls, which appear from their 

 hardness to be of a chitinous consistency. The region of the case 

 which lies furthest away from the external orifice of the sperma- 

 thecal sac has a, relatively speaking, thin wall which is di\dsible 

 into two layer's. The outermost layer is apparently softer than 

 the inner layer and is dai^kly stained ; it has a granulai- appear- 

 ance. The inner layer is stratified longitudinally, in a direction, 

 that is to say, parallel to the long axis of the case. It is but 

 slightly stained, but it has a granular aspect ; and hei-e and there 

 ai'e darkly stained particles within its walls. At the base, the 

 part which corresponds to the " cup " of the acorn, the walls are 

 very thick indeed, so much so as to leave the barest chink in the 

 way of a lumen leading to the exterior of the case. At the 

 opposite exti-emity, I should say, the case is perfectly closed, and 

 has no communication with the interior of the spermathecal sac. 

 Where the walls are thick the process of cutting the sperm-case 

 into sections has broken v;j) the walls here and there into parallel 

 sti'ips I'unning parallel again to the long axis of the case. 



So much foi' the sti'ucture of the spermatophores and the 

 enclosed sperm-ropes in Poly tor etitus kenyaensis. In the allied 

 P. montis-kenyce the conditions were different. In none of the 

 specimens which I examined — and these were numerous, though 

 not so numei-ous as of P. kenyaensis — did I observe any large 

 spei'inatophore lying within the spermathecal sac at the mouth. 

 On the othei' hand, the interior of the spermathecal sac near to 

 its blind end was occupied by a lai-ge number of spermatophores 

 of the type already stated to exist in the species Polytoreutus 

 violaceus and P. hindei. These spermatophoi'es, that is to say, are 

 of the same form as in P. kenyaensis and P. magilensis, but are 

 larger and thicker, the increased size being mainly due to the fact 

 that the heads of the spermatozoa are covei'ed externally with a 

 refracting and non-staining chitinous coat, which is absent in the 

 more slender sperm-ropes of the other two species. I think that 

 it will be convenient to retain the term sperm-ropes for the 

 agglutinated spermatozoa of P. kenyaensis and P. magilensis, and 

 to call speimatophores these moi'e thoroughly finished off struc- 

 tures in P. violaceus, P. hindei, and P. montis-kenyce. It seems 

 to me also that the use of these difierent terms will serve to 

 emphasize an essential difference between these two kinds of 

 masses of agglutinated spermatozoa. In P. montis-kenym each 

 mass of spermatozoa has its own chitinous case ; in P. kenyaensis 

 a large number of sperm-masses are enclosed within the same case. 

 There is an analogy here with the cocoons of the Oligochfeta. In 

 some forms the cocoon contains but a single Qgg ; in others a 



