the Radicle and Germen of Seeds. 81 



seeds of gourds, to the circumference of wheels, similar to 

 those upon which I bound germinating seeds, each piece of 

 metal being perforated near its more pointed and smaller end, 

 and fixed to the wheel by a pivot, round which it was left at 

 liberty to revolve. When these pieces of metal were sub- 

 jected to the operation of centrifugal force, their heavier ends 

 necessarily receded from the axis of rotation, and the lighter 

 ends were necessarily made to point towards it. M. Poiteau 

 conceives that nothing more occurred in my experiments and 

 those of M. Dutrochet, who repeated the same experiments 

 with very superior machinery, and with the same results ; and 

 that the sole cause why the germs approached the axis of rota- 

 tion was, that their specific gravity is not greater than one-third 

 that of the radicles. I was not so fortunate as to be able to 

 comprehend this ; and though I gave M. Poiteau full credit 

 for accuracy respecting the different degrees of specific gravity 

 of the substance of the radicles and germs, I thought the fact 

 a very extraordinary one. I therefore planted a couple of 

 dozen seeds of the plant (phaseolus vulgaris) which was the 

 subject x)f M. Poiteau's experiment, and I then discovered, to 

 my astonishment, I confess, that the radicles, instead of pos- 

 sessing a degree of specific gravity three times greater than 

 that of the germs, were really the lighter body of the two, the 

 germs having all sunk to the bottom of the same vessel of 

 water in which all the radicles rose to the surface. I. repeated 

 this experiment several times, and always with the same 

 result, having detached both the radicles and germs from their 

 cotyledons as soon as the germs became visible above the sur- 

 face of the ground. 



The seeds in my experiments were bound firmly to the cir- 

 cumference of the wheels, instead of being, as M. Poiteau's 

 pieces of metal were, left at liberty to revolve upon pivots; and 

 the direction taken by the radicles and germs of seeds is 

 totally independent of each other. The germ is never made to 

 deviate, in any degree, from its perpendicular line of growth 

 upwards by any obstacle which the radicle meets with in its 

 descent; nor is the direction of the radicle ever influenced, in 

 any degree, by that taken by the germ. If the seed of a 

 peach, or pear, or other tree which nature intended to support 

 VOL. II. Aua. 1831. G 



