BOTANY. 



EFFECTS OF MOONLIGHT OX VEGETATION. 



PROFESSOR LIXDLET, in his new edition of The Tlieory and Practice of Horticul- 

 ture, makes the following remarks on the effects of moonlight upon vegetation : 



" As far as is yet known, solar light alone has the power of producing any 

 practical effect upon vegetation. That of the moon has, however, been shown 

 to be not without influence. That the moon has a great mechanical effect 

 upon our globe is undisputed. Of this, we need not say that the perpetually 

 alternate ebbing and flowing of the tide afford the most evident proof. But, 

 whilst the effects of the moon are admitted to be extremely powerful in this 

 respect, the influence of her light, except as regards illumination, has been often 

 considered by scientific men as inappreciable ; and the proverbs to the contrary, 

 current among the unlearned, have been accordingly estimated as popular errors. 

 It has, however, been at last demonstrated that the moon's rays are very 

 far from powerless. "We learn from a note by M. Zantedeschi ( Comptes Rendus, 

 October, 1852), that these rays do affect vegetation. This philosopher states 

 that the influence, physical, chemical, and physiological, of the moon's light, 

 which has hitherto been the object of so much research and speculation 

 amongst scientific and agricultural writers, has been recently investigated by 

 him in consequence of his having had occasion to give a historical summary 

 of the works on the subject. In the course of his inquiries he found it neces- 

 sary to clear many doubtful points, in doing which his attention was forcibly 

 arrested by the movements exercised in mere moonlight, under certain circum- 

 stances, by the organs of plants ; and this led him to make the whole subject a 

 serious and profound study. His observations were commenced in 1847, in the 

 Botanic Garden at Venice; they were continued in 1848 in the Botanic Gar- 

 den at Florence, and at Padua in 1850, 1851, and 1852. In the whole series 

 of his experiments, M. Zantedeschi always remarked certain motions in plants 

 having a delicate organization as soon as they were brought under the influ- 

 ence of the lunar rays. In those experiments the rays were always diffused, 

 being neither concentrated by lens nor mirror. Such movements .could not 

 be obtained by the action of heat, in whatever way thermal influences were 

 applied. It was in vain to elevate or depress the temperature ; in the absence 

 of moonlight the phenomena in question could not have been elicited. The 

 plants on whidi M. Zantedeschi principally experimented were Mimosa ciliata 

 Mimosa pudica, and Desmodium gyrans. He always took great care to 

 determine exactly the position of the leaf stalks and leaflets of the plants after 



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