33 



are manifested in such infinite variety at the time of fer- 

 tilization, 



M. DeCanclolle, who has noticed this phajnomena, ascribes 

 it, with some doubt, to the " low degree of elasticity resident in 

 the flower stalk," (Physiologie Vegctale, i. 14) ; M. Morren's 

 researches have led him to a very different conclusion. He 

 found that the non-elasticity of the flower-stalk, when moved 

 horizontally, exists only so long as it adheres to the stem, and 

 that when it is cut off it indicates abundant elasticity in all 

 directions ; and the eventual result of his enquiries was that, 

 after all, the catalepsy of this plant is only sham. I now quote 

 the author literally. — " In fact, if the flower-stalk is elastic 

 when cut ofi^, why should it be cataleptic while adhering to the 

 stem ? I therefore removed from a stem, with very sharp 

 scissors, a bract quite down to its base ; I then turned the 

 flower to the right, when it sprang back to the left, and vice 

 versa ; so that under these circumstances the elasticity was 

 restored and the catalepsy gone. This curious experiment, 

 the precise and positive result of which was really surprising, 

 always succeeded ; and if an observer were not to push his en- 

 quiries any further, he would conclude that the phaenomenofii 

 is dependent upon the bracts ; it will be seen that in point of 

 fact there is no catalepsy at all." 



Other experiments shewed that by cutting away half a 

 bract, dividing it from the point to the base through the mid- 

 rib, the flower recovered its elasticity on the side whence the 

 bract was removed, but remained destitute of it on the side 

 where the bract was uninjured ; so that by such a contri- 

 vance, a flower can be brought into a state of elasticity on one 

 side and of catalepsy on the other ! It is however necessary 

 to cut away the bract down to the point of its insertion, other- 

 wise the apparent catalepsy is not destroyed. 



M. Morren observes that these curious phaenomena are 

 wholly dependent upon the peculiar arrangement and propor- 

 tion of the flower-stalks and bracts, and that they are merely 

 mechanical. It appears that each pedicel reposes in a bract 

 channelled like a gutter, and that its length is a trifle more 

 than half the breadth of the bract at its base, and it is in this 

 circumstance that the whole secret lies. The bract is much 

 more rigid than the flower-stalk, is immoveable, and is placed 

 close to the flower ; when the flower is turned to one side the 

 base of the calyx, which forms a projection above the flower 



U. 3 fay, 1840. e 



