230 VOCABULARY. 



they are popularly confounded. The batrachians are cold- 

 blooded and oviparous, and in most living species are with- 

 out scales, and the blood is partly aerated through the skin. 

 The young, for the most part, breathe by gills like those of 

 fishes; they assume a fish-like form (as the tadpole), and 

 finally, when adult, with few exceptions, lose their gills and 

 breathe by lungs, like true or scaly reptiles. They generally 

 have limbs, but not always. Johnson's N. U. Cyc. 



BIFURCATION. (A fork.) Division of a trunk into two 

 branches, as the bifurcation of the trachea, aorta, &c. 



BUCCAL. That which concerns the mouth, and especially the 

 cheek. 



C. 



CAECUM. The blind gut ; so called from its being perforated at 

 one end only. That portion of the intestinal canal which is 

 seated between the termination of the ileum and beginning 

 of the colon, and which fills, almost wholly, the right iliac 

 fossa, where the peritoneum retains it immovably. Its length 

 is about three or four fingers' breadth. The ileo-caecal valve, 

 or valve of Bauhin, shuts off all communication between it 

 and the ileum, and the ' Appendix vermiformis caeci' is at- 

 tached to it. 



In the horse the caecum (water stomach) will hold four gal- 

 lons. A horse will drink at one time a great deal more than 

 his stomach will contain ; but even if he drinks a less quan- 

 tity, it remains, not in the stomach or small intestines, but 

 passes to the caecum, and is there retained, as in a reservoir, 

 to supply the wants of the system. Youatt. 



CAL/CULUS. A diminutive of ' calx,' a lime-stone. Calculi are 

 concretions, which may form in every part of the animal 

 body, but are most frequently found in the organs that act 

 as reservoirs, and in the excretory canals. They are met 

 with in the tonsils, joints, biliary ducts, digestive passages, 

 lachrymal ducts, mammae, pancreas, pineal gland, prostate, 

 lungs, salivary, spermatic, and urinary passages, and in the 

 uterus. The causes which give rise to them are obscure. 

 Those that occur in reservoirs or ducts are supposed to be 

 owing to the deposition of the substances, which compose 

 them, from the fluid as it passes along the duct ; those which 

 occur in the substance of an organ are regarded as the pro- 



