TRUE DARWINISM 167 



But here lies a difference. In garden plants the seeds 

 taken from o^ie individual parent-plant may grow up into 

 several different forms in the same garden. Thus an eminent 

 agriculturist speaking of the great variability of wheat, said 

 that one could almost raise a new variety from every grain in 

 an ear ! In Nature nothing of this has ever been observed ; 

 but the many varieties of the above-named plants, as recorded 

 in our " Floras," are found scattered over the country, and are 

 often known as "local varieties". Thus, Sir J. D. Hooker 

 observes ^ of the innumerable forms of Hawkweed (Hieraciuni) 

 — " variable as the genus is, the sequence of its forms is so 

 natural as to have been recognised by all botanists. This 

 sequence represents to a considerable extent the spread of the 

 forms in altitude and area in the British Isles." 



I will take another instance from Sir J. D. Hooker's Studenfs 

 Flora, viz., the Knotgrass {Polygonum Aviculare). Speaking 

 of its varieties he refers them to their localities as follows : 

 P. Aviculare, proper; Var. P. littorale, littoral, the passage to 

 P. maritif?ium ; Var. agrestinum, field form ; arenastrum, sand- 

 loving form ; inicrospermuni, small-fruited ; rurivagum, a way- 

 side one, sub-sp. P. Roberti ; Var. P. Raii, sandy shores. 



The simple interpretation of all these "forms" or "varie- 

 ties," is that they have been evolved under and through the 

 conditions of the particular localities in which they are found 

 respectively. 



While some genera would, therefore, seem to be endowed 

 with a very active variability, quickly incited into action by 

 local circumstances; others, like the daisy, bluebell, heath, 

 plantains and grasses remain the same wherever they grow. 



We do not know why some plants vary so greatly under 

 cultivation and others do not; nor why some species have no 

 varieties, while others have many in Nature. Such, however, 

 are observed and well-known facts. 



I would now emphasise more particularly the marked 

 differences noticeable between variations under cultivation and 



^ Student's Flora, 3rd. ed., p. 232. 



