CH. VIII] REPRODUCTION. 109 



and numerous offspring come to be the most important 

 part of its physiological equipment. 



The value of reproduction comes out clearly in those 

 plants which regularly exhaust themselves by yielding seed 

 and die in the process of reproduction. This is the 

 case with annuals, which start as seedlings in the 

 spring, yield seed in the autumn and then die. It is 

 clear that seed-production is what kills them, because if 

 they are prevented from setting seed, they will survive. 

 Here the individual is sacrificed to the good of the 

 community : the species (or group of individuals) lives on 

 in the seeds, while the individual plants die. All the 

 machinery of the individual, its manufacture of organic 

 material with the help of chlorophyll, and its consequent 

 storage of starch and other reserve material, are directed 

 to the very thing which kills it, viz. the production of a 

 big seed crop. The life of the species is the really 

 important thing, the life of the individual is important 

 because it renders reproduction, i.e. the continuance of the 

 species, possible. This sounds paradoxical, but I believe 

 the machinery of living things to be more comprehensible 

 if it is thought of as being directed to the preservation of 

 the species rather than of the individual. 



Some forms of reproduction are comparatively simple. 

 In the tulip-bulb a bud developes in the axil of a leaf, 

 exhausts the old bulb, and carries on the life of the plant. 

 Again in the bramble the branches in autumn grow down 

 to the ground and put out adventitious roots, and in the 

 spring the bud at the end of the branch shoots out anew. 

 Again many water plants habitually detach parts of their 



