BuRTONj on a Portable Revolving Table. 
9 
pacitVj I know him to be a cannibal. A large tadpole^ and 
especially if he be hungry, will kill and devour his smaller 
brethren ; while the body of a dead tadpole put into a jar of 
living ones is attacked in a moment_, and greedily consumed 
as a bonne bouche of the highest order. These ferocious 
qualities are not found in the frog. Again, Dr. Carpenter 
observes, " The development of the locomotive poivers, which 
may be regarded as an indication of the general activity of 
the organic functions, will be found peculiarly connected with 
that of respiration." Now, in the tadpole we have the 
development, first, of the tail, an active and vigorous organ 
of locomotion, and which is often large enough to make a 
winding sheet for the whole body; and, secondly, the 
development of the four extremities, the locomotives of the 
future frog, which business is completed during the tadpole 
state. 
Thus there seems to be plenty of evidence that some pro- 
vision exists in the tadpole for a much higher aeration of the 
blood than the mere reptile arrangement will permit. And I 
submit that if we have been able to trace each of the three 
great arterial trunks into immediate connexion with the 
lungs themselves — the cephalic running over, or rather form- 
ing, the upper edge of the lung, and directly receiving blood 
from branches of the pulmonary artery ; the pulmonary , dis- 
tributed to the lung itself; and the aortic y also penetrating 
the chamber of the lung to inosculate with, and receive blood 
from, the pulmonary — then ^ve have discovered this pro- 
vision, and have found an adequate explanation for all those 
active vital phenomena in the tadpole which appear to indi- 
cate a very complete aeration of the blood. 
On a Portable Revolving Table. 
By John Burton, Esq. 
(Read Oct. 9th, 1861.) 
A communication of Mr. Jansen in the Journal for 
July suggested to me the desirableness of laying before the 
Society a portable revolving table which I had recently con- 
structed for my own use. 
Where only one microscope is used, an apparatus to move 
