ANNUALS 71 



produced the more of its substance is scattered and 

 lost to the individual. 



It is on the other hand the race as a whole which 

 is benefited, for obviously the larger the number of 

 seeds, and the stronger the young plants produced each 

 year, the more rapidly will the race increase in numbers 

 and spread over new land. 



We must think, therefore, of every plant as being 

 engaged in two great kinds of work. One, to make 

 itself as strong as possible, and protect itself from any 

 injury, and the other to produce as many and as healthy 

 new plants as possible, to carry on the next generation. 



These two functions are to a great extent antagonistic ; 

 for instance, it requires time for a tree to grow large, so 

 that its leaves are well out of reach of every grazing 

 animal and its roots deep enough down to get water 

 even in hot weather. And while it is merely growing, 

 a smaller plant may have matured and shed thousands 

 of seeds, which growing up quickly multiply again in 

 their turn, and thus that race of plants may become 

 far more numerous and more widely spread than 

 that of the tree. 



Every plant then in striving to carry on these two 

 works to the best of its power under the peculiar 

 circumstances in which it is placed, has to make some 

 sort of compromise between them and thus it is 

 that we get so many different kinds and sizes of 

 plants. 



Some take only a few weeks or a month to grow 

 up from seed, produce flowers and scatter their seeds. 

 Plants which do this between one growing season and 

 the next are termed annuals. Naturally they have 



