630 THE AMERICAN NATURALIST. 
the space in segments two and three of the abdomen, before 
descending on each side to swell and form the seminal vesicles. 
From these vesicles the ducts run slightly up and back to a 
common opening situated between the points of attachment of 
the two pairs of the dorso-ventral muscles of these appendages. 
The accessory glands, which are larger in the male than in the 
female, appear to open into the atrium at a point just posterior 
to the orifice of the vasa deferentia. The exact courses of the 
vasa deferentia and the accessory glands are extremely difficult 
to follow. In places the walls of the ducts entirely disappear, . 
leaving only as a guide, in the case of the vasa deferentia, 
the contained spermatophores. In some specimens the whole 
anterior portion of the abdomen is packed with spermatophores. 
Fig. 6 is a diagrammatic drawing of a longitudinal section 
through a male Koenenia, taken to one side of the sagittal 
plane. Only the testis and vas deferens, with the accompany- 
ing accessory glands of one side, are shown. There are, evi- 
dently, delicate muscles in the walls of the testes. In the 
posterior ends of the testes are numerous cells which are 
undoubtedly sperm mother-cells, while the anterior portion 
appears to be crowded with small dotted packets. These 
dots, which must necessarily be the spermatozoa, glisten under 
transmitted light and rarely show a stain, even with iron- 
haematoxylin. Nowhere throughout the whole course of these 
organs is there any trace of spermatozoa possessing flagella. 
It must be that, in Koenenia, the condition is retained which 
is found in most crustacea, which possess non-motal sperma- 
tozoa often imbedded in gelatinous spermatophores. It 15 
probably due to this spermatophore secretion that the sperm 
cells almost entirely refuse to take on the stain. 
UNIVERSITY oF TEXas, AUSTIN, TEXAS, 
May 23, 1901. 
