74 MY LIFE 



The special points of interests in the above letter are its 

 complete confirmation of the views derived from European 



plant-, as to use of the colours of fruits in indicating those 



which arc edible for birds or arboreal mammals, while the 



few exceptions as regards colour arc of those large and very 

 sweet fruits whose attractions are sufficient without the signal 

 of bright colour. Again, the very frequent occurrence of 

 acrid or poisonous juice or milk in the hark and leaves, pro- 

 tecting the young shoots and trees from herbivorous animals, 

 combined with perfectly innocuous and often agreeable fleshy 

 or juicy fruits in order to assist in their dispersal, so clearly 

 implies a selective agency in two opposite directions in the 

 same species, as almost to amount to the required demonstra- 

 tion of the existence of natural selection. 



I cannot forbear calling attention to the extremely careful 

 wording and punctuation of these letters, written from a sick 

 couch, and of which I have not altered a word or a comma. 

 The clearness and accuracy with which the information is 

 conveyed fittingly corresponds with the writer's careful obser- 

 vation of every aspect and detail of plant life. Had his health 

 permitted more continuous work for a few years longer, he 

 would probably have given us a volume upon all the chief 

 aspects and relations of the vegetation of the forests and 

 mountains of equatorial America, which would have been of 

 the greatest scientific and popular interest. 



