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RESEARCHES ON LIGHT.

another possessing different powers, upon the exercise ofwhich the structural formation of the plant depends; andin the autumnal season these are checked by a mysteriousagency, which we can scarcely recognise as heat, althoughconnected with thermic manifestations, upon which appearsto depend the development of the flower and the perfec-tion of the seed.

(402.) A few remarkable results must yet be noticed.Under all ordinary circumstances plants bend in a verydecided manner towards the Light. Tn all my experimentswith red fluid media they have as decidedly bent from it. 1do not know how to explain this as the effect of mereheat; it would appear that some property resides in thered rays which acts in opposition to the general law. Fur-ther investigations arc required on this point.

(400.) The soil in which the plants grew was the samein all the boxes used, but it was several times observedthat, under the yellow glasses and fluids, fungi made theirappearance. From the occurrence of these vegetablesunder the same circumstances on several occasions, 1 wasnaturally led to observe their production with greatercare. 1 could not, with the utmost attention, make theAgaricus muscarius grow behind any other absorbentmedia than the yellow, under which it grew luxuriantly.This appears, in some measure, to explain the popularnotion, that mushrooms, and plants of that variety, growmost abundantly under the influence of bright moonlight.It has been found that the heat of the rays of the moon isvery limited, and the amount of chemical action which hasbeen detected is exceedingly small; we must thereforeregard the moonbeams as consisting largely of the lumi-nous rays, the other active rays being in all probabilityabsorbed by the moon’s surface.

(404.) The changes which take place in the seed during