20 



ELEMENTARY STUDIES IN BOTANY 



a vegetative cell of a many-celled plant divide's, the result is 

 usually the addition of new cells to the body, so that there 

 are no new individuals, but 

 the old individual grows. 

 In other words, the cell- 

 division which results in 

 reproduction among one- 

 celled plants usually re- 

 sults only in growth among 

 many-celled plants. In a 

 certain sense, any such 

 growth is reproduction, for 

 new cells are produced, but 

 we are using the word re- 

 production in the sense of 

 producing new individuals. 



FIG. 15. (Edogonium: A, part of a filament, one of whose cells has formed a single 

 large swimming spore with a crown of cilia ; B, part of a filament showing antheridia 

 (a) from which two sperms (b) have escaped, a vegetative cell with its nucleus, and 

 an oogonium (the large round cell) filled by a large egg packed with food and whose 

 nucleus is seen (d) , and which a sperm has entered (c) ; C, a swimming spore with its 

 crown of cilia ; D, a young plant developing from the swimming spore. 



It is quite evident, therefore, that this process of cell- 

 division goes on in all plants, and that in the lowest it is 

 the only method of reproduction. 



