336 



LAWS OF VARIATION. 



Chap. XXV. 



southern parts of Europe, withstood the intense cold better 

 those with lighter complexions from the north • 



statements are liable 



but no doubt 



In the second chapter on Selection I have given several 

 proving that with animals and plants diffei 



colour are 



elated with constitutional differences, as shown by g 

 less immunity from certain diseases, from the attacks of para 

 plants and animals, from burning by the sun, and from 

 action of certain poisons. When all the individuals of any 

 variety possess an immunity of this nature, we cannot feel 

 that it stands in any sort of correlation with their colon r • 



when several varieties of the same species, which 

 coloured, are thus characterised, whilst 

 are not thus favoured, we must 



coloured 



ir ; but 

 milarly 



believe in the 



•relation of 



kind 



of 



Thus in the United States purple- 

 fruited plums of many kinds are far more affected by a certain 

 disease than green or yellow-fruited varieties. On the other 

 hand, yellow-fleshed peaches of various kinds suffer from another 

 disease much more than the white-fleshed varieties. In the 

 Mauritius red sugar-canes are much less affected by a particular 



disease than 



the most liable to mildew 



White onions and verbenas are 

 Spain the green-fruited grapes 



suffered from the vine-disease more than other coloured 

 Dark-coloured pelargoniums and verbenas are more scorched by 

 the sun than varieties of other colours. Eed wheats are believed 

 to be hardier than white ; whilst red-flowered hyacinths 

 more injured during one particular winter in Holland than 

 coloured varieties. With anirm 



were 



white 



suffer most 



parasitic worm 



from the distemper, white chickens from a 



their tracheaa, white pigs from scorching by the sun, and 



cattle from flies ; but the caterpillars of th 



yield white cocoons suffered 



parasitic fungus than those producing yellow silk 



Ik-moth which 

 France less from the deadly 



The cases of immunity from the action of certain vegetable 

 poisons, in connexion with colour, are more interesting, and are 



present wholly inexplicabl 



I have already given a remar 



able instance, on the authority of Professor Wyman, of all the 



ho 



*s, excepting 

 Virginia from 



those of a black 



colour 



g the root of the Lachnanthes 



suffering severely 



t 





* 



