BOTANICAL SUBJECTS. 95 



variation. This plasticity is supplied chiefly V)y sexual conjugatiou 

 of different but allied individuals. It is necessary also that this 

 fitting should be slow, to make it stable. 



This slowness is provided for by heredity, which restrains a too 

 rapid variation. Nevertheless, "jumps" or "breaks," as horti- 

 culturists call them, now and again occur, in the process of 

 multiplication, which may fit bodies more quicMy to their sur- 

 roundings, than by the slow steps severely controlled by heredity.* 



Gralton, in his " Natural Inheritance," p. 34, says, " Evolution 

 need not proceed by small steps only," but also hy jumps. Although 

 intermediate forms may be in existence, it does not at all follow 

 that they had anything to do with the evolution of the type we 

 call a, jump. I do not find anything to disagree with in all this. 

 We may not exactly know the cause of the " jump," but we know 

 that in the crossing of cultivated plants, " breaks " or jumps do 

 occur, both as regards form and size of foliage, habit of plant, 

 form and colour of flower, &c. 



Without the faculty of seeing what is beyond our immediate 

 senses, that is, without the helpful faculty of a discriminating 

 imagination, we cannot understand a possible state of things 

 which may somehow have occurred prior to the present state of 

 things, which we can see and understand. To an evolutionist, some 

 previous state or states, out of which the present has come, 77iust 

 have existed. The difficulty is to discover what lines evolution 

 took, from a simpler to a more complicated state. For this purpose 

 a vivid imagination, held in control by facts, is indispensable, so 

 that we may frame before the mind's eye a period and conditions 

 long anterior to the present mode of evolution. We have to take 

 into consideration that the present state of things is the result of 

 millions of generations. By persistent inheritance, variation 

 through sexual crossing, and through other factors of variation, 

 and by the strictest selection, they have evolved characters, which 

 apparently mask and belie their true origin. A clear view of a 

 possible past is needed to understand the present phenomena, 

 because the present is often only a more complicated mode of 

 blooming of the past. Therefore, somehow or other, unless all 

 past forms and structures have become irretrievably extinct, and 

 totally new creations have all along come out, we ought to be 

 able to trace back at least some of the present structures to more 



* Vide Discussion on " Fusion." 



