124 BUFONIDA. 
chicken inoculated with it received no injury, it does not 
appear to be noxious when absorbed, and carried into the 
circulation. 
“Dr. Davy thinks that the principal use of this poison 
is to defend the reptile against the attacks of carnivorous 
animals; he also remarks, that as it contains an inflamma- 
ble substance, it may be excrementitious ; it may serve to 
carry off a portion of carbon from the blood, and thus be 
auxiliary to the function of the lungs. In support of this 
idea, the author observes that he finds each of the pulmo- 
nary arteries of the Toad divided into two branches, one of 
which goes to the lungs, and the other to the cutis, ramify- 
ing most abundantly where the largest follicles are situated, 
and where there is a large venous plexus, seeming to indi- 
cate that the subcutaneous distribution of the second branch 
of the pulmonary artery may further aid the office of the 
lungs, by bringing the blood to the surface to be acted upon 
by the air.” * 
I have extracted the latter part of this passage to shew 
how beautifully the independent observations of two phy- 
siologists, so eminent as Dr. Davy and Dr. William Kd- 
wards, bear upon and illustrate each other; as will be 
obvious to every one who recollects the account I have 
already given of the cutaneous respiration of the amphibia, 
as discovered and explained by the last-named philosopher. 
The usual pace of the Toad is neither leaping nor run- 
ning, it is rather a kind of crawl; and on being alarmed, or 
threatened with danger, it stops, swells its body, and, on 
its being handled, a portion of the cutaneous secretion 
which I have just mentioned exudes from the follicles, and 
a discharge of the limpid water, which has been before 
* Abstracts of the Phil. Trans. Part II. p. 263. For the whole paper see 
the Phil. Trans. for 1826, Part II. p. 127. 
