INSECTS AND FLOWERS 225 



In one sense, at least, a conspicuous flower may 

 be regarded as the creation of countless generations of 

 insects which have come and gone through the ages. For 

 while the colours and perfumes of flowers entice the insect 

 from afar, and direct its passage to the nectary, their 

 varied forms and mechanisms minister to the comfort of 

 the visitor, even as they ensure a ready traffic in pollen. 

 All these marvellous adaptations are the actual outcome 

 of the process itself. The Rev. G. Henslow tells us that 

 "just as a muscle increases with use, so does the proto- 

 plasm of plants respond and cause the structure which 

 contains it to adapt itself by growth in various ways to 

 the weights, thrusts, &c, which it receives." Those primi- 

 tive flowers which responded most successfully to the 

 weight of insects standing upon them transmitted to 

 posterity — not, perhaps, the enhanced stability acquired in 

 their short struggle for supremacy, but the inborn capacity 

 to respond again and again with ever increasing effect. 

 The same principle underlies all the adjustments of flowers 

 to insects, whether of colour, form, or mechanism ; while 

 the insects themselves must have been modified recipro- 

 cally, though probably in a less degree. 



The elaborate adjustment of a flower to a particular 

 insect visitor is almost always accompanied by a reduction 

 in the amount of pollen produced, and a conservation of 

 the nectar from unbidden guests — i.e. insects which are 

 unable to effect cross-fertilisation. Flowers such as the 

 wild rose and the poppy, that secrete no nectar, have very 

 numerous stamens which produce large quantities of pollen 

 — doubtless to offset that which the insect visitors devour. 

 Such blooms may be regarded as primitive, at least in so 

 far as their adaptation to insects is concerned. This is 

 apparent when we compare them with a more highly 

 specialised flower, such as the white dead-nettle (Lamium 



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