CHAPTER XI 



REPRODUCTION 



THE life of every organism has two aspects : the 

 vegetative, or individual, aspect, and the reproduc- 

 tive, or tribal, aspect. In the one case all the energies 

 of the organism are devoted to its own individual 

 nourishment, protection, and so forth ; in the other, 

 certain organs come into play, previously in abey- Antag- 

 ance or up to that time non-existent, the activity ""dividual 

 of which, since they are, as a rule, incapable of nourish- and tribal 

 ing themselves, immediately brings about a drain 

 upon the vegetative organs. Further, among the 

 higher forms, the offspring are, for a time at least, 

 dependent on the parent for support, and this con- 

 stitutes a further drain on its resources. Hence we 

 see that tribal life must be antagonistic to indi- 

 vidual life. Indeed it may be said, at least in general 

 terms, that whatever conditions are favourable to 

 vegetative development are against the interests of 

 the reproductive processes, while the reproductive 

 processes must of necessity react adversely on 

 the vegetative system. Thus gardeners prune fruit 

 trees when they wish them to bear fruit, or re- 

 move the flowers when they desire plentiful foliage. 

 Keeping this fact in mind, let us inquire into the 

 different modes of increase presented by plants and 

 animals. 



As we have already seen in Chapter II (p. 8), Asexual 

 at or before the completion of, or at some period ^epro 



i_ ! T P ,1 . , .r. . tion. 



in, the lite cycle or the plant or animal, provision is 



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