224 PHYSIOLOGY AND NATURAL HISTORY. 



were necessary to avoid the objections which might be founded upon the influence 

 of humidity or any other atmospheric variation. They were kept in the dark 

 during the whole day; when the days preceding the full moon arrived, they were 

 carried, after 3 a. m., always to the same place to be exposed to its rays: but two 

 of the pots were uncovered, and two protected from the rays by an opaque body ; 

 the others were freely exposed to the open air and all its influence. 



After six nights' exposure, the difference in the coloration was very marked : 

 the little plants constantly protected from the influence of light were white ; and 

 those exposed to the lunar rays had a yellowish tint, which appeared to be chang- 

 ing to the green colour. 



I desired to repeat also the experiment of Vassalli. I had only made obser- 

 vations upon leaves perfectly closed, and little shoots, of no vigour, drooping over 

 the edges of the pots wherein they had germinated. After that, I tried exposing 

 various specimens of Mimosa pudica to the action of the moon's rays for an hour 

 during full moon. I was delighted to see the little shoots rise after a quarter of 

 an hour's exposure ; the plants were at the distance of a feW millemetres from the 

 edge of the pot ; in half an hour the stems were straighter, and in an hour and a 

 half they had attained the height of more than 2 inches ; but I could not detect 

 any sensible opening of the leaves. This experiment appeared necessary in order 

 to confirm what has been said of the influence of the rays of the moon upon the 

 growth of the Mimosa, because this fact, more or less established by Vassalli, has 

 not been received with entire confidence by other authors ; and in this last experi- 

 ment I took precaution of placing near the Mimosa exposed to the lunar rays 

 another of the same plants covered with an opaque body, which shielded it from 

 the light : in this no movement was produced. The experiment was repeated six 

 times with constant results. We may therefore believe that the growth of the 

 little stems of the Mimosa is to be attributed solely to the influence of the moon's 

 rays. 



I made these experiments in the summer of 1847 ; and I have thought it neces- 

 sary to enter into details, because I was able to make certain, by a great number 

 of observations, frequently repeated, that the difference of temperature, of the 

 movement of the air, and exposure to different degrees of light, had an influence 

 upon the more or less prompt and more or less perfect manner in wliich the leaves 

 of the Mimosa open and close. 



One morning in the month of July, aboul; 5 o'clock, in the Botanic Garden of 

 Venice, two plants of Mimosa pudica, kept in a conservatory (perfectly expanded), 

 presented an aspect of luxuriant vegetation. Another, exposed in the open air, 

 had its leaves entirely closed and the stems bent. A fourth, placed in another 

 part of the garden was half-closed. On the day preceding, the gardener had, at 

 my orders, shut up the last in a dark place three hours before sunrise. 



I took care also to verify the influence exerted upon the Mimosa by the artificial 

 light of a lamp, and I found the growth was from 3 to 5 centimetres. 



CARPENTERIA AND DUJARDINIA. 



The number of the Annals of Natural History for November, contains an inter- 

 esting communication from Dr. J. E. Gray of the British Museum, on the discovery 

 of an animal forming a connecting link between Rhizopoda (Foratninifera) and 



