III.] IS THE GERM-PLASM LOCALIZED? 101 



moist soil, and they may be carried far down streams or 

 distributed along lake shores; the may -apple and a host 

 of rhizomatous plants march onward from the original 

 starting-point ; the bryophyllum easily drops its thick 

 leaves, each one of which may establish a new colony 

 of plants; the leaves of the lake -cress {Nasturtium 

 lacustre) float down the streams and develop a new plant 

 while they travel; the house -leeks surround themselves 

 with colonies of offshoots, the black raspberry travels 

 by looping stolons, and the strawberry by long runners; 

 the tiger -lily scatters its bulb -like buds, and all bulb- 

 iferous plants spread quite as easily by their fleshy parts 

 as by seeds. Now, all these vegetative parts, when 

 established as independent plants, produce flowers and 

 good seeds, and these seeds often perpetuate the very 

 characters which have originated in the asexual gener- 

 ations, as we have seen in the case of many bud -varie- 

 ties; and it should also be remarked that these phytons 

 usually transmit almost perfectly the characters acquired 

 by the plant from which they sprung. Or, to put the 

 whole matter in a convenient phrase, there may be, and 

 is, a progressive evolution of plants without the aid of 

 sexual union. 



Now, where is Weismann's germ -plasm? One of the 

 properties of this material — if an assumption can receive 

 such designation — is its localization in the reproductive 

 organs or parts. But the phyton has no reproductive 

 parts; or, if it has them, they are developed after the 

 phyton has lived a perfectly sexless life, and possibly 

 after generations of such life, in which it and its progeny 

 may either have remained comparatively stable or may 

 have varied widely, as the circumstances may have 

 determined. If the sex -elements of any flower, there- 



