the other of nervimotion, which depends upon some sti- 
mulus applied to the surface of the leaflets, unaccompanied 
by actual violence, such as the solar rays concentrated in 
the focus of a lens.. As in all cases, the bending or folding 
of the leaves evidently takes place from one leaf to another 
with perfect continuity, it may be safely inferred, that the 
invisible nervous action takes place in a direct line from 
the point of original irritation, and that the cause by which 
this action of neryimotion is produced must be some in- 
ternal uninterrupted agency. This was, after much curious 
investigation, determined by the author to exist neither in 
the pith, nor in the bark, nor even in the cellular tissue 
filled with neryous corpuscles, and on which he supposes 
the locomotion of the swelling at the base of the petioles to 
depend. It is in the ligneous part of the central system, 
in certain tubes supplied with nervous corpuscles, and 
serving for the transmission of the sap, that Dr. Dutrochet 
believes he has found the true seat of nervimotion, which 
he attributes to the agency of the sap alone, while he con- 
siders the power of locomotion to depend upon the nervous 
corpuscles alone. 
Without subscribing to this doctrine, unless with some 
exceptions, such, for instance, as to the essential difference 
between locomotion and nervimotion, which are, perhaps, 
capable of being identified, we cannot but express our 
admiration of the industry, dexterity, and philosophical 
acumen displayed by the author in every part of his work, 
which is well deserving the attentive consideration of all 
physiological botanists. ip 
