DEVELOPMENT AND IMMATURE STAGES. 179 



which lie like nests in the ground- plasma ; these often 

 unite with those adjacent to them, and thus form radial 

 strings of nuclear matter. 



In the adult female small particles of the nuclear 

 substance separate themselves and form irregular- 

 shaped pieces which wander to the periphery of the 

 gland ; immediately under the exterior surface they 

 separate and form distinct, almost hemispherical nuclei 

 (germato-blasts) which are surrounded by a thin layer 

 of protoplasm, and protrude in a dome-shaped manner 

 from the surface, but finally separate themselves from 

 it entirely. 



From the above account it is evident that the dis- 

 tinction between germ-cells which are developed from 

 distinct cells and those differentiated from the nucleus- 

 holding protoplasmic layer is not of importance. 



The epithelium-like cells of the periphery of the 

 ovaries, especially those near the anterior pole, grow 

 rapidly and assume the character of egg-cells ; these 

 cells remain unaltered during the ecdyses and may be 

 recognised in the virgin female. 



After the receptaculum seminis has attained a certain 

 size its wall bends out in two places ; at the same time 

 the wall of each ovary buds out below the oviduct ; 

 these projections from the ovaries and the receptaculum 

 grow in length, and finally join. The two ovaries at 

 this time are joined by a fine string of cells. The 

 ovaries continue to move backward, and the recep- 

 taculum to increase in size ; the ovaries in like degree 

 approach the receptaculum. The connecting string on 

 each side increases in diameter and a lumen appears 

 in it ; so that free communication between the recepta- 

 culum and the ovaries is established. 



The further changes by means of which the inner 

 sexual organs of the female assume their complete 

 condition, as well as the development of the external 

 organs, are carried out during the ecdysis. The ex- 

 ternal opening is shifted forward as the oviducts 

 increase in length; the lateral supporting-pieces arise at 



