GRAFTS. 267 



affected by the changes in the cell-protoplasm 

 which nourishes it when the reproductive cells are 

 forming. 



In the case of graft-hybrids the matter appears 

 to be somewhat different, and we may well 

 suppose, with Strasburger, that the commingling 

 of characters observed in flowers, fruits, foliage, 

 etc., on shoots borne after grafting are due to 

 the occurrence of nuclear fusions during the 

 union of the grafted tissues ; though it is by no 

 means impossible that what has really happened 

 is profound alterations in the nuclear substance 

 (germ-plasm) owing to its being nourished by 

 cell-protoplasm (somato-plasm) which has been 

 itself affected by the interchanges of substance 

 between scion and stock, and therefore itself 

 furnishes a different nutrient medium from the 

 unaltered cytoplasm of either. 



But even here we can find parallels among the 

 ordinary phenomena of plant reproduction. Maize 

 plants with white endosperm containing starch, if 

 crossed by pollen from other plants with purple 

 endosperm containing sugar, bear seeds with 

 purple endosperm containing sugar, and such 

 Xenia may be compared to graft-hybrids in many 

 respects. 



I know of no case among fungus infections 

 which could be compared directly with these 

 examples, and it is not at all likely that we 

 shall meet with any instance of a fungus-hypha 

 handing over nuclear substance to an egg-cell, 

 and so affecting the latter that an embryo results. 



