GENITAL ORGANS. 



347 



number of nutritive cells in the ovary, the germ- or terminal chamber 

 is extremely large. In this connection it has been maintained that 

 the various cell-elements of the Insectan ovary originate from indif- 

 ferent cells (Korschelt, Xo. 155, Wielowiejski, and others). 



The ventral cell-strand (cz) becomes transformed in the proximal 

 part of the oviduct, which widens into a cup and receives the 

 separate ovarian tubes. The transformations which take place in 

 the male will be described later. 



The extent of the coelomic sacs, during the further course of 

 development, becomes much restricted through the degeneration of 





-> 



9 



Fig. 173.— Longitudinal section through the female genital rudiment of Phyllod-omia genua 

 (after Heymons). In A, the development of the ovarian tubes is beginning. In B, they have 

 advanced further, cz, rudiment of the efferent genital ducts; cf, terminal filaments; ep, 

 nuclei of the epithelial cells ; gz, genital cells. 



those parts of them which extend into the limbs (p. 320), by the 

 development of the fat-body (Figs. 169,/, and 170, fk), and through 

 the separation of the somatic and the splanchnic mesoderm-layers 

 (Fig. 170, so, sp). Only a small portion of them (c) finally remains, 

 bounded laterally by the rudiment of the pericardial septum (ps), 

 and internally by the terminal filament of the genital gland (ef). 

 The dorsal region, where these two lamellae pass into each other, 

 seems to be intimately connected with the cardioblasts (It). The 

 strand-like genital rudiment now appears attached to the terminal 

 filament as to a mesentery (Fig. 170, gz). 



