CHAPTER III. 



REPRODUCTION AND GERMINATION. 



31. Nature of reproduction and germination. 



One of the chief purposes of every plant is to give rise to simi- 

 lar individuals, or to others which will reproduce the species. 

 This is accomplished in a great variety of ways, all of which 

 fall into two general classes, according to the manner by which 

 the new individuals originate. By one method specialized 

 masses of protoplasm from different parts of the body of the 

 same or different individuals are brought together and allowed 

 to fuse, producing a single cell, or protoplast, which is known 

 as an egg, and its formation constitutes sexual reproduction. 

 The uniting masses of protoplasm in sexual reproduction are 

 unlike, and are generally incapable singly of producing an in- 

 dividual of the typical kind. The mechanism of sexual repro- 

 duction may not be adequately presented, without a study of 

 the minute structure and action of the fusing protoplasts, and 

 should be taken up in more advanced studies of the subject. 



By a second general method, a single cell or mass of cells 

 may give rise to a new individual, constituting a non-sexual re- 

 production. In some instances single cells known as spores 

 are separated, and give rise to the new plant ; in other cases 

 masses of cells known as gemma are cut off and serve the 

 same purpose ; while in still other cases an entire organ, or a 

 part of it, may be separated from the plant, and may then grow 

 and regenerate the missing organs in such a manner as to give 

 rise to a new and complete individual. Formation of new 

 plants by gemmae, and from organs or parts of organs, may be 



