CHAPTER XXX 

 REPRODUCTION 



Pray tell us from whence this impertinence springs, 

 The sexes at once to confound. 



— Whitehead. 



Organisms, in general, sooner or later die. The length of life 

 varies with different species and individuals, but after some months 

 or years (in some cases even hours or days) external or internal 

 conditions become unfavorable for life and the existence of the 

 individual, as such, ends. If a species is not to become extinct, 

 some provision must be made for reproduction or the formation 

 of new individuals, since only those organisms which have this 

 power can survive in the struggle for existence. 



Vegetation and Reproduction. — All useful structures and re- 

 sponses have one of two purposes; they serve either (1) to keep 

 alive the individual organism which possesses them or (2) to 

 keep alive the race (species). The former structures are called the 

 vegetative ones and the latter the reproductive. As ordinarily cata- 

 logued, the root, stem, and leaf comprise the vegetative organs, 

 while the flower, fruit, and seed are the reproductive structures. 



The question sometimes arises as to which of these two func- 

 tions is the more important,— vegetation or reproduction,— the 

 life of the individual or the life of the race. The answer depends 

 simply upon the point of view. To the individual, his own life 

 is the more important, but if we judge by the facts of human ex- 

 perience, from the point of view of nature (assuming that nature 

 has a point of view) the life of the race is much the more important. 

 Individuals rise and fall, wars between individuals and species 

 with their millions of slaughtered dead come and go, but the race 

 continues. Nature seems to care little about individuals; with 

 her it is the species that counts. 



Nature of Reproduction.— Reproduction commonly implies 

 (1) separation from the parent plant, (2) rejuvenation, and (3) mul- 

 tiplication. The young which result from reproduction lead a life 

 distinct from the parent and start out with rejuvenated proto- 

 plasm. While multiplication is often one of the most striking 



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