ORGANIC RESPONSE 



295 



years ago. The phylloxera, a relative of the corn- 

 root aphis already described, infests the roots of 

 grape-vines. The introduction of this pest into 

 French vineyards threatened their rapid destruction 

 until it was discovered that the wild varieties of 

 American grapes are immune to the insect. Ameri- 

 can stocks were planted, upon which were grafted 

 the French varieties of grape, 

 thus defeating the phylloxera, 

 while at the same time pre- 

 serving the peculiar qualities 

 of the French fruit. 



Grafting is also possible 

 between animals. Tadpoles, 

 moth-pupae, worms, etc., may 

 be cut in pieces and fastened 

 together in all sorts of ways 

 without destroying individual 

 life and growth. Even in 

 mammals, various organs 

 have been transplanted from 

 one animal to another (of the same species) with- 

 out loss of function. A practical application of the 

 same principle is used by surgeons in starting a 

 healing-process in large burns on the human body 

 by the grafting on of bits of skin taken from another 

 person. 



FIG. 107. A common 

 method of grafting : A, inser- 

 tion of two scions into cleft of 

 stock at cambium (growing) 

 region ; B, wound protected 

 with wax to prevent drying 

 out of tissues. (From Curtis, 

 after Bailey.) 



