IMPORTANCE OP PLANT VARIATION. 87 



lias been changed, the number of flowers being reduced from six or more 

 to two or three. It has a close resemblance to a potato, it has been 

 grown for fifty years. Among other cultivated plants that show points 

 and characteristics which are fixed as well as characteristics can be fixed, 

 are the bush lima, the bush bean, different varieties of corn, the moss rose, 

 and many other plants. 



I know the argument against giving these widely different varieties 

 a place as species is that they have been brought about through the 

 influence of man. and furthermore it would be very confusing to syste- 

 matic botany on account of so many intervening gradations; but if the 

 theory of evolution is true it must also be true that these intervening 

 forms still exist between the newly formed species, because in many 

 cases they have been nursed along by man and not allowed to become 

 extinct, in other cases they have not had time to be crowded out of the 

 race. Their existence is proof that species are being made at the present 

 time. 



There is no doubt but what the forms of plants have been influenced 

 by the dominating force which existed during the period when a given 

 plant species was formed. If there is any truth in the belief that some 

 plants have developed special forms to withstand droughts; or spines 

 to protect themselves against the destruction of wild animals, it must 

 be true that the large animals of creation have played an important part 

 in the evolution of plants. If the larger animals, which are products 

 of a natural creation, took part in the evolution of plants, it is but logi- 

 cal to believe that man, another product of a natural creation, should 

 take a part in a natural evolution of plant species. 



If man is a natural force which is an active influence in the devel- 

 opment of new forms then new species do originate in the garden, and 

 it seems as though they should be recognized by the systematic botanist 

 and given a place in the great system of classified plant forms. 

 F. A. LoEw, 



Botanical Laboratory, Agricultural College. 



