OF SEED-SAVING. 171 



lence exists, it will continue, by the action of endos- 

 mose, to be attracted thither more powerfully than to 

 any other part, and the effect of this will be the 

 starvation of the seed : but a scanty supply of food, 

 an unhealthy condition of the plant itself, or with- 

 holding the usual quantity of water, will all check 

 the tendency to luxuriance, and therefore will favour 

 the developement of the seed, whose feeble attracting 

 force is, in that case, not so likely to be overcome by 

 the accumulation of attracting power in the neigh- 

 bouring parts. Thus we see the Pine-apples are 

 more frequently seedful under the bad cultivation of 

 the Continent, than in the highly kept and skilfully 

 managed pineries of England. Abstraction of 

 branches, in the neighbourhood of friiit, has also been 

 occasionally found favourable to the formation* of 

 seed ; evidently because the food that would have 

 been conveyed into the branches, having no outlet, is 

 forced into the fruit. 



Another cause of sterility is the deficiency of pollen 

 (87) in the anthers of a given plant, as in vegetable 

 mules (88), which usually partake of the spermatic 

 debility so well known in similar cases in the animal 

 kingdom. It has often been found that sterility of 

 this kind is cured by the application, to the seedless 

 plant, of the vigorous pollen of another less debilitated 

 variety. 



In some plants, such as Pelargoniums, when culti- 

 vated, the anthers shed their pollen before the stigma 

 is ready to receive its influence, and thus sterility re- 

 sults. All such cases are provided for, by employing 



