124 BUFCWIDja. 



chicken inoculated with it received no injury, it does not 

 apj^ear 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. 11 * 



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 Ed- 

 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. 



