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On the movement of the leaves of the Drosera ; & on their power of detecting carbo nitrogen compounds.

by C. Darwin Esq. F.R.S.

Being struck with surprise at the number of insects caught chiefly Diptera, 1860 caught by the common sundew (Drosera rotundifolia) date) on Ashdown Forest in Sussex, & reflecting on the case of the Dionœa I was led to make the f[illeg] following observations.

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I was not then aware that such facts had been observed &c & which were pursued to during 1862

I took by chance a dozen plants by chance, which bore 56 fully expanded & fresh leaves; & of on 31 of them I found that 31 had caught dead insects or remnants of them; on one plant with six leaves each had its insect.

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: nor does This gives the full [illeg] of insects caught, as several of the leaves had caught more than one;  almost certainly and some of the younger leaves would probably have succeeded in capturing prey, & some of the older leaves, may have caught, & quite subsequently rejected their prey in the manner presently to be described.— Imitation with a stiff camel camel-pencil without any object placed on the leaf— causes the viscid hairs to close in. The movement is increasingly slow & takes from about to hours; but it is impossible to ascertain the time with any accuracy as the age of the leaf & apparently general state of the plant or of the temperature causes much difference. Every object, whether organic or inorganic, & when placed very gently on the leaf, so as to cause as little irritation as possible, caused the hairs to collapse close inwards.

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I [pencil text not transcribed] *