282 



The Plant World. 



tions showing a purely physiological reaction between scion and 

 stock may be mentioned. 



In the leaves of Epiphyllum are found certain albumen 

 bodies not found in the leaves of the related plant Peireskia. 

 Mitosch grafted Epiphyllum upon Peireskia stocks and in the 

 leaves of the latter which subsequently developed these bodies 

 were formed. That such phenomena are not necessarily of 

 general application is shown by the results of Meyer and Smith 

 who grafted Datura stramonium upon Solarium tuberosum and 

 determined that the alkaloids of the former were not to be found 

 in the latter. Also L. Guignard selected plants which contain 

 cyanogenetia glucosides and made giafts between these and re* 

 lated forms which do not produce these compounds. His re- 

 sults show no transfer of the glucoside or glucoside forming 

 capacity from stock to scion or scion to stock. 



On the other hand that pronounced physiological influences 

 do pass between stock and scion is demonstrated by many in 

 vestigators. L. Paniel studied the photosynthesis and respira- 

 tion of species of Artemisia and Plagius when giafted upon Arte* 

 misia stock as compared with similar ungrafted plants. With 

 Artemisia these functions were much less active in the grafts than in 

 the checks, while in the case of Plagius the grafted plants decom* 

 posed more carbon dioxide and liberated more than twice as 

 much of this gas as did the checks. C. Laurent found grafted 

 forms of cabbage to contain an increased, amount of crude fiber 

 and saccharine matter and a decrease in total ash content, 

 though certain of the ash constituents were increased. Grapes 

 grafted upon different stocks Laurent found to show differences 

 in composition, as well as resistance to fungus diseases. Later 

 the same author gives results of analyses of stems and leaves of 

 grafted and ungrafted cabbage, and seeds of grafted and ungrafted 

 beans which show that the grafting affects certain functional 

 capacities of the stock as indicated by changes in the chemical 

 composition. 



S. Riviere and G. Bailkache have shown that variations of 

 color, size, content of sugar and acid, and also dry matter ill 

 apples and pears occur when grafted on different stocks. More 

 recently the same authors have made careful analyses of grapes 

 grown upon their own roots and upon the roots of ten other va- 



