SEED IN WISTARIA. SINENSIS. 91 



(186G, p. 401), a paper from my pen on the Consumption of 

 Force in overcoming Gravitation by Plants. I gave an account 

 of experiments and observations, showing that the effort of a plant 

 to elevate itself above the surface of the earth was a heavy draft 

 on nutrition, and just so much diverted from vegetative growth. 



One of my illustrations was furnished by the common Chinese 

 Wistaria. When a branch is allowed to run along the ground, 

 over a tree or fence, or nailed against a wall, or is in any w r ay sup- 

 ported instead of having to support itself, it grows w r ith wonderful 

 rapidity. I have known branches under these circumstances grow 

 30 feet in one season ; and I believe much greater growths than 

 this are on record. In America nurserymen make tree Wistarias 

 by training a branch up a stake to any given height, which after 

 two or three years is able to sustain the head when the stake is 

 taken away. No matter how rich may be the soil, or how favour- 

 able may be the circumstances under which the plant is growing, 

 the most vigorous annual growths on these heads seldom exceed 

 3 or 4 feet. I know of perhaps one hundred of these tree Wis- 

 tarias from ten to twenty years old in my own vicinity ; and I 

 have never seen one that ever made a shoot w r hich in one season 

 touched the ground, though the stems may not have been more 

 than from 4 to 6 feet high. Similar facts are set forth in detail 

 in the paper I have referred to. 



In 1868 I made another observation on these " tree Wistarias," 

 which was also published in the same ' Proceedings ' (see vol. xx. 

 p. 314, 18G8), that these " tree " forms produced seeds abun- 

 dantly, while those which were supported by extraneous means 

 rarely yielded any. 



It is a matter of common note that the Wistaria, as usually 

 seen both in America and Europe, rarely seeds. Of course vege- 

 table physiologists had already know r n that a distinction had to be 

 made between vegetative force and reproductive force. They are 

 not antagonistic; but one grows out of or supplements the 

 other. A young tree does not commence seed-bearing till the 

 exuberance of its early life is checked. To some extent the two 

 forces do seem antagonistic. The youngest and most vigorous 

 tree can be made to flower if a ring of bark be taken from it ; and 

 a graft from a vigorous young tree produces fruit very soon when 

 worked on a tree of bearing age, though its parent tree may not 

 assume the reproductive condition for years to come. Still the 

 antagonism is not distinctive ; for there is a manifest coexistence 

 between the two forces. 





