ALG^E 



369 



the egg is called an oogonium; cells which produce sperms 

 are called antheridia. Oogonia and antheridia are sex 

 organs. 



Another very significant thing is to be noted in connec- 

 tion with (Edogonium. It is the oospore which, protected 

 by a thick wall, survives through the winter. When this 

 oospore germinates in the spring it does not grow directly 

 into a plant hke the one which produced it. It sub- 

 divides into four cells, and each one of these four cells may 



Fig. 166. — (Edogonium. A, the oospore (fertilized egg) escaping from the heavy 

 wall which surrounded it. B, the oospore after germination divided into four 

 large zoospores. C, the zoospores completed and ready to escape. 



then produce a new plant. (See Figure 166.) In this matter 

 the fertihzed eggs of plants generally show a distinct differ- 

 ence from the fertilized eggs of animals. The eggs of 

 animals in nearly all cases directly produce forms like 

 their parents. The egg of (Edogonium does not, however, 

 directly produce a form like its parent. It first produces 

 a number of spores and each one of these may become a new 

 plant. This is important for the reason that this habit 

 of the egg, the habit of producing something different from 



