STUDY OF CHROMOSOMES OF LACHNOSTERNA. 85 



The testes, although of an unusual shape, show the seriation 

 of the stages clearly, being but a modification of the simple 

 straight (orthopteran) type with a linear seriation of the cells. 

 In the species studied, the testes consist of a great many follicles 

 radiating from the center. Fig. 2 represents a diagrammatic 

 section through the center of the testis and perpendicular to its 

 broad surface. In the center of the testis from which the follicles 

 radiate (Fig. 2, A), one finds all the spermatogonia and here new 

 cysts are in the process of formation. On each side of this 



FIG. 2. Diagrammatic section through testis at right angles to its broad surface, 

 to show seriation of stages. .4, region in which are all spermatogonia; B, early 

 growth stages and synezesis; C, pacyhtene and later growth stages; D, maturation 

 divisions; , spermatids and spermatozoa; F, cavity in testis where spermatozoa 

 are retained prior to discharge from testis; G, efferent duct. 



region (B, B} are the early synaptic stages (synezesis). In the 

 regions C-C one finds the later synaptic stages (pachytene and 

 diplotenes), while in regions D-D show most of the spermatocyte 

 divisions; regions E-E contain most of the spermatids and 

 spermatozoa. The chamber (F) shown in the figure serves as a 

 place where the spermatozoa are collected and stored prior to 

 discharge from the testis; the duct (G) leads from the storage 

 chamber. Of course the stages above seriated overlap and 

 there is no sharp delimitation as is diagrammatically shown in 

 the figure. The formation of the cysts in the region A was 

 followed out and my observations confirm those of Wieman ('10) 

 and Hegner ('14) that each testicular cyst is derived from a single 

 spermatogonium. There is, however, no evidence that cell 

 division is by amitosis as Wieman found. 



