STUDIES ON GERM CELLS 



451 



Fig. 23 A, oocyte of the cat, showing the 'corps enigmatique' (c.e) ; (redrawn 

 from van der Stricht, '11). B, one germ cell and several somatic cells from a 

 guinea-pig embryo; (redrawn from Rubaschkin, '12). C, two germ cells from the 

 embryo of Lophius with plasmosome extruded into cytoplasm; (redrawn from 

 Dodds, '10). D, germ cell of chick, showing 'Netzapparat' ; (redrawn from von 

 Berenberg-Gossler, '12). E, a germ cell of Raja batis, filled with yolk material 

 and surrounded by somatic cells; (redrawn from Beard, '02). F, oogonium of a 

 sponge, (redrawn from Jorgensen, '09). 



is the only vertebrate in whose primordial germ cells an extra- 

 nuclear body has been fomid. 



Rubaschkin, in 1910, announced the results obtained with the 

 eggs of the guinea-pig by certain methods designed to bring 



