kind, which it will soon overwhelm in the struggle for 

 existence. Such a sudden change, if of conspicuous 

 advantage, will therefore become fixed ; if not of so much 

 importance, it will generally be obliterated by being bred 

 out by the average. 



All plants vary in at least minute details from their 

 ancestors, but cross-fertilisation tends to keep them about 

 the mean. Fruits of an advantageous type are of such 

 great importance that we can readily understand their 

 assuming many forms within the scope of one family. And 

 as their possibilities are limited, it is also easy to under- 

 stand how the same type may be developed in many parts 

 of the vegetable kingdom. These sudden changes in 

 organisms are responsible for the enormous variety of 

 plants and animals in cultivation. A man does not cause 

 the variation, though he may assist; but when a difference 

 suddenly presents itself he enables it to be maintained and 

 continued by preventing it being bred out by the average 

 or common form. 



It is rather interesting to note that throughout the 

 Roses the colour blue appears absent from its flowers. 

 You find red, yellow, white, alone or variously mingled, 

 but never blue. You find a somewhat similar condition in 

 our native Heath. While in Asters the conspicuous flowers 

 may be any shade of blue, red, white, but never yellow. 

 The use of colour is for the purpose of attracting insects, 

 and blue and red colours appear to attract principally in 

 day time ; yellow and white are more conspicuous in the 

 dull light of evening and night. There is one class of 

 naturalists who love to see an accurate purpose in every 

 detail of nature. When this is carried to excess it tends 

 first to deceive, and then to disappoint the young student, 

 and neither of these conditions are to his .benefit. There 

 are in nature innumerable marvellous adaptations, but rb 

 is going altogether too far to claim that every modification 

 we find in a plant has some adaptive advantage. On the 

 contrary, probably in every plant there are many minor 

 structures and qualities that are there as purely negative 

 conditions. They are of no distinct use, nor would their 

 suppression materially benefit the plant. We should be 

 more correct in saying that though a plant must be adapted 

 to its surroundings, yet none is exactly adapted. If it were 

 so, no variation could be to its advantage, and we know 

 variation is the rule, not the exception. Heath and Roses 

 set seed equally well whatever tint their petals may be. 



