70 INTERNAL ORGANS. 



chambers of the heart which are observable through 

 the skin in the backs of caterpillars." 



/A Ji Ml JI II uk 



The heart of the cockchafer, with its valves, chambers, and 

 artery, from M. Straus Durckheim. 



This is both very rational, intelligible, and supported 

 by minute and careful observation. It at once de- 

 stroys numerous fancies on the subject, proposed by 

 Cuvier and Marcel de Serres. 



The blood then appears to be partly prepared by 

 transmission through the coats of the intestine, and 

 again probably undergoes changes in its passage to, 

 and its course through, the heart; and being diffused 

 through the cavity of the body without being confined 

 in blood vessels, it is probably distributed whither it is 

 wanted by the muscular movements of the animal, 

 and assimilated by what is termed imbibition. 



Organs of Breathing. 



Ih the larger animals, the blood, by means of lungs, 

 is exposed to fresh air, taken in by the mouth and 

 nostrils, and through the windpipe passing into the 

 lungs, where it gives off oxygen to the blood, and car- 

 ries off carbonic matter from the blood. In insects 

 there are no lungs, and consequently no air is taken 

 in by the mouth (there are no nostrils) by breathing. 



