XVII THE METHOD OF ORGANIC EVOLUTION 351 



dental variation, we have to ask why the several kinds 

 of variation occurred together, or why neither of them 

 occurred in the numerous species in which to be eaten 

 would be injurious instead of beneficial ? 



But if we begin at the same stage and apply the 

 Darwinian theory we find that the whole process is easy 

 of explanation. It is an observed fact that fruits vary in 

 softness, juicyness, and colour, and seeds in the hardness 

 or hairy ness of their integuments. Any variation of 

 primitive fruits in either of these directions would there- 

 fore be beneficial, by attracting birds to eat them and so 

 disperse the seeds that they might reach suitable stations 

 for development and growth. Such favourable variations 

 would therefore be preserved, while the less favourable 

 perished. 



Now ask the same questions as to the production of the 

 innumerable modes of dispersal of seeds by the wind, from 

 the simple compressed form and dilated margins of many 

 small seeds, to the winged seeds of the ash and maple, 

 and the wonderful feathery parachute of the thistle and 

 the dandelion. Or again, inquire as to the wonderful 

 springed-fruits which burst so as to scatter the small 

 seeds, as in some of the balsams ; or yet again, as to the 

 sticky glands of the sundews, and the small water-traps of 

 the bladder-wort ; and a hundred other equally strange 

 adaptations to some purpose of use to the species, but whose 

 development has no relation whatever to any possible 

 direct action of the environment, though all of them are 

 explicable as the result of the successive preservation of 

 such variations as are known to occur, acting at various 

 intervals and by means of successive modifications, 

 during the whole period of the development of the group 

 from some remote ancestral form. 



The modern advocates of Lamarckism content them- 

 selves with such simple cases as the strengthening or 

 enlarging of organs by use, the hardening of the sole of 

 the foot by pressure, or the enlarging of the stomach by 

 the necessity for eating large quantities of less nutritious 

 food. These, and many other similar modifications, may 

 doubtless be explained by the direct action of conditions. 



