189 



extremely vascular nature of the organ. — I am happy in being also 

 able to adduce, in evidence of the fact, the names of Professors 

 Jacob and Harrison, who witnessed the recent injection of the vessels, 

 and who can bear testimony to their magnitude and numbers. 



The exact mode of termination of the ultimate vessels in the 

 tongue may not be easily ascertained, but from the extremely fine 

 ramifications which are perceptible in it, I am inclined to think that 

 it is by a congeries of vessels, the termination of arteries and com- 

 mencement of veins, without the intervention of a spongy or caver- 

 nous texture.* And if this were established it would, in my opinion, 

 afford a still farther confirmation of the analogy between the erectile 

 portion of the chameleon's tongue and the corpus cavernosum, 

 for that the latter is purely a vascular body, without any interme- 

 diate cells between its arteries and veins, many experiments and ob- 

 servations have satisfied me. 



The heart in t!ie chameleon consists of one ventricle (Fig. 6, s.) 

 and two auricles (t.l) with each of which is connected a large 

 sinus (v.) for receiving the blood of the body and tongue. — 

 This remarkable cavity between the veins and auricles has never, 

 that I am aware of, been before noticed in this animal. The 

 French Academicians have described the auricles as being large, and 

 the left in the chameleon which they dissected was the more capaci- 

 ous : but they have made no allusion to distinct sinuses apart from the 

 auricles. In both those which I examined these sinuses were well 

 marked ; the right, however, exceeded by one half in magnitude 

 the left, and formed a larger cavity than both the auricles taken- 



* The minuteness of the globules of the blood in this animal, which renders it highly diffuse., 

 able, appears particularly favourable for making observations on the magnitude of its ultimate 

 vessels ; for with a glass one could discover vessels tinged with the coloured parts of the blood, 

 which were not visible to the naked eye. 



