270 DISEASE IN PLANTS. 



natural grafts, a probability not diminished by the 

 fact that such roots cross at many points, and are 

 easily grafted. 



Notes to Chapter XXIX. 



The student should read Bailey, The Nursery Book, 1896, 

 for details regarding the practice of grafting, and facts in 

 abundance can be obtained from the pages of the Gardeners^ 

 Chronicle. 



Concerning graft-hybrids and the variations of grafted 

 plants see Jouin, Cati Hybrids be obtained by Grafting? and 

 especially Daniel, " La Variation dans la Greffe," in Attn, 

 des Sc. Naturelles, S. VIII., Vol. 8, 1898, p. i, and the 

 literature there collected. The whole subject is largely con- 

 troversial, and much work remains to be done. 



