74 THE SURVIVAL OF THE UNLIKE. lu. 



sexual or gametophytic generation does not arise, in the 

 flowering -plants, until the plant arrives at the stage of 

 seed -production. Where does the germ-i)lasni reside in 

 the sporophyte ? All these facts and conclusions are 

 inconsistent with Weisniannisra as taught at present, 

 and these alone would lead nie to discard the hypothe- 

 sis for plants, however well it may apply to the animal 

 kingdom. 



Henslow has made a different argument to show that 

 the germ -plasm of plants may be directly exposed to 

 external influence (Origin of Floral Structures). The 

 germ -plasm is assuraably located in the sex -elements in 

 the flower, and the egg -cell of the embryo -sac and the 

 ^ sperm -cell of the pollen grain are close to the surface, 

 p^cx. and are directly impressed by the interference of bees 

 and other external stimuli. Henslow endeavors to show 

 • "that the infinite variety of adaptations to insects dis- 

 coverable in flowers may have resulted through the direct 

 action of the insects themselves, coupled with the respon- 

 sive power of protoplasm." And these characters must 

 be in part acquired during the lifetime of a given indi- 

 vidual. 



2. It seems to me, also, that the presumption, upon 

 general philosophical grounds, is against the doctrine 

 that immediate external influences are without permanent 

 effect. If we admit — as all philosophers now do — that 

 species are mutable, and that the forms of life have been 

 shaped with reference to their adaptations to environ- 

 ment, then we are justified in assuming that every 

 change in that environment must awaken some vital re- 

 sponse in the species. If this response does not follow, 

 then environment is without influence upon the organ- 

 ism; or if it follows and is then not transmitted, it is lost 



