PANGENESIS. 169 



The retention of dormant gemmules, and their 

 passage from generation to generation until their 

 development, may seem improbable; but is it more 

 so than the fact which their presence would explain 

 — viz. the transmission of latent structures and their 

 ultimate reappearance ? 



The development of the whole plant from a 

 Begonia leaf implies that these gemmules are very 

 widely distributed through the tissues. 



The elective affinity of the gemmules for the cells 

 which precede them in growth may be paralleled b}^ 

 the affinity of the male and female germ-cells, as we 

 see in the preference of a plant for the pollen grains 

 of its own over those of closely-allied species, or by 

 the attraction of the minute germs of disease to 

 certain tissues of the body. 



It is possible that the numerous gemmules thrown 

 off by the cells of a complex structure, such as a 

 feather, " may be aggregated into a compound gem- 

 mule." In the case of a petal, however, where parts 

 as well as the whole are apt to develop, as is seen in 

 the case of " stripes of the calyx assuming the colour 

 and texture of the corolla," it is more probable that 

 the gemmules are separate and free. The cell itself 

 is a complex structure, and we do not know whether 

 its separate parts are not developed from the separate 

 gemmules of an aggregate. 



Such an hypothesis explains the fundamental 

 similarity which has already been shown to exist 

 between all modes of reproduction. The gemmules 



