COLEOCH^TE. 



93 



tion. In the withdrawal of the chloroplast into the base of the egg- 

 cell, and the formation of a receptive spot, Coleochcete is paralleled 

 by both (Edogonium and Vaucheria. 



Soon after entering the oogonium the spermatozoid penetrates the 

 egg, a membrane is formed about the latter, and the sperm-nucleus 

 wanders toward that of the egg (Fig. 33, F). Before final fusion 

 takes place, one or more changes occur in the egg, which may be 

 worth noting. The chloroplast which lay at the bottom of the egg, 



FIG. 33. Fecundation in Coleochcete pulvinata. (After Oltmanns.) 



E, mature oogonium, egg rounded off. 



F-H, oSgonia with fecundated eggs; male nucleus in F applied to that of egg; both nuclei 



in resting stage. 



G, a little later than F ; the chloroplast has taken a lateral position in egg. 

 H, fusion of sexual nuclei complete. 



as previously stated, divides, and the two resulting chloroplasts take 

 positions on opposite sides of the egg (Fig. 33, G). The egg and, 

 consequently, the ventral part of the oogonium increase in size ; in the 

 former vacuoles appear, and the nuclei which are in the resting con- 

 dition fuse completely (Fig. 33, H). 



For the further behavior of the oospore and its germination, which, 

 as is well known, bears a tolerably close resemblance to such liver- 

 worts as Riccia, the reader is referred to the original papers of 

 Pringsheim and Oltmanns. 



