ANATOMY OF THE CROCODILE. 
413 
to the one purpose of slaughtering prey. The victim 
that could not be destroyed by being kept under 
water was killed by being thrown out of it. 
In consequence of the manner in which the negro 
butchers detached the heart and other viscera, we 
lost the traces of the provision which exists in this 
reptile for circulating, by a trilocular heart, pure ar- 
terial blood in the anterior parts of the body, and 
mixed venous and arterial blood in the hinder mem- 
bers, by a junction of the pulmonary artery with the 
aorta descendens, low down in the back. The dif- 
ference of the two qualities of the blood in the cir- 
culatory systems of the two extremities was, however, 
very perceptible, by the absence of all red blood in 
the hind limbs and tail, and by the presence of bril- 
liant arterial blood in the fore parts and the head. 
‘‘ The stomach of the Crocodile bears considerable 
resemblance to the gizzard of a bird. Several stones 
swallowed to assist digestion, render the similarity 
perhaps more obvious than even the form and struc- 
ture. The Crocodile we were skinning and cutting 
up had evidently prowled along the coast before he 
had entered the pond in which he had been caught ; 
for his stomach was filled with marine crabs half 
digested ; and the stones found in it, if necessary on 
ordinary occasions to triturate its food, were es- 
sentially requisite now to crush the hard cases of 
Crustacea. 
“ The dilatations and contractions of the thorax 
when sensitiveness was excited by the pain attendant 
on the first removal of the skin, showed the degree in 
which the ribs by their mobility assisted respiration. 
