a portion of the pith on which nitric acid had been acting, 
and the mixture was exposed to the heat ofa lamp. Being 
examined after a few minutes, the globules were found to 
have resumed their natural appearance. This curious fact 
indicated, in the opinion of Dr. Dutrochet a strong and 
unexpected point of analogy between plants and animals 
According to the microscopical researches of some modern 
observers, it has been ascertained that all the organs of 
animals are composed of a conglomeration of minute cor- 
puscles, similar to those just described; the corpuscles 
which constitute the muscles are soluble in acids, but 
those which compose the nervous system are insoluble in 
the same acids, and only soluble in alkalies. Now, as the 
chemical properties and the external appearance of the | ; 
particles scattered among the cellular tissue of plants, and 
constituting the nervous system of animalsare the same, the - 
author is induced to infer that the spherical particles of 
plants are in fact the scattered elements of their nervous 
system. This hypothesis receives additional strength from 
the great similarity which exists between the medullary 
substance of the brain of Mollusca Gasteropoda and the 
cellular medullary tissue of plants. In pursuit of this idea, 
Dr. Dutrochet made a variety of experiments upon the 
sensitive plant, the results of which seem to be these. The 
principal point of locomotion, or of motility, exists in the little 
swelling which is situated at the base of the common and 
partial petioles of the leaves; ‘this swelling is composed 
of a very delicate cellular tissue, in which is found an 
immense number of nervous corpuscles; the axis of the 
swelling is formed of a little fascicle of tubular vessels. 
It was ascertained by some delicate experiments that the 
power of movement, or of contraction and expansion, exists 
in the parenchyma and cellular tissue of the swelling, and 
that the central fibres have no specific action connected 
with the motion. It also appeared that the energy of the — 
nervous powers of the leaf depended: wholly upon an 
abundance of sap, and that a diminution of that fluid 
occasioned an extreme diminution of the sensibility of the 
leaves. Prosecuting his remarks yet further, the author 
ascertained, that in the motion of the sensitive plant two 
distinct actions take place, the one of locomotion, which is 
the consequence of direct violence offered to the leaves, 
and which occurs in the swellings already spoken of; 
