of the Royal Academy of Paris, for 1824. $05 
the gills, which derive their nerves from this source. If they 
be destroyed, the motions of the opercula are lost, and respi- 
ration ceases. The same effect follows from dividing them 
longitudinally. M. Flourens concludes that the cerebral organ 
of inspiration is found here, circumscribed, distinct, and de- 
veloped to a true lobe, while in other animals it is scarcely 
separated from the mass. Similar phzenomena are to be ob- 
served in the Gadus lota, pike, and eel. 
The conclusion to be drawn by the author and those who 
coincide in his views respecting the hollow tubercles is, that 
the point in which the brain in fishes most essentially differs 
from that of other classes, consists in the great development of 
the part which presides over the respiratory function; which 
M. Flourens accounts for by the more laborious respiration of 
aquatic animals, who act on the air through the intervention 
of water, unlike animals respiring in air which immediately 
penetrates the lung. 
It is thus, says he, that the brain is larger in animals en- 
dowed with much intelligence, the cerebellum in birds, which 
are so much -more agile than any other, and that this same 
cerebellum always disappears in reptiles, sluggish animals, the 
very name of which implies torpor. The author finally ex- 
presses an opinion that the parts which render the animal 
tenacious of life, and especially the spinal marrow, are with 
respect to volume in an inverse ratio to those upon which the 
intellectual functions depend; animals destitute of the means 
of defence from violence require a blunted or coarse descrip- 
tion of vital condition, which should be to them what we might 
designate a detence against the effects of its own peculiar con- 
dition. 
M. Flourens being obliged to make so many and such ex- 
tensive wounds of the brain to resolve questions so important 
to humanity, took the opportunity of making numerous ob- 
servations respecting injuries of this organ and the regenera 
tion of its coverings, as also upon the corresponding phzeno- 
mena in the animal’s faculties as the reproductions advance. 
To analyse these observations made day after day would re- 
quire a copy of them, and the details would prove equally in- 
teresting in this point of view, if our limits permitted us to 
enumerate them. In general, where a portion is removed, a 
clot of blood is formed, and a scab produced, beneath which 
lymph is deposited. ‘The bone extoliates; beneath this ex- 
Dliation and scab a new skin forms which casts them off, and 
beneath this skin a new bone forms; but this new skin does 
not consist of true corium or rete mucosum, nor is the bone 
formed with two laminz: and a diploe. ‘The new skin is con< 
Vol. 67. No. 386. April 1826. 2Q tinued 
