GLOSSARY 373 



Bradypus {brad' i pus). A genus of sloths. 



Bronchiole (brong' ki ole). One of the smaller branches of the bronchi, air tubes in 

 the lungs. 



Bronchus (brotig' kus) (pi., brouchij. One of the two main branches of the trachea 

 in many vertebrates. 



Brown, Robert, British botanist, 1773-1858. 



Bryozoa {bri' o zo' a). A group of marine and fresh-water animals of uncertain rank 

 and relationships, mostly colonial, bearing tentacles, and commonly known 

 as moss animals. Sometimes placed in a phylum with the Phoronidea and 

 Brachiopoda. 



Buccal cavity {bitk' k'l). The most anterior division of the digestive tract of an earth- 

 worm. Also the mouth cavity of other animals. 



Budding. Division of an organism into unequal parts in reproduction. 



Buflfon, Comte de {bufo^'). French naturalist, 1707-1788. 



Bufo. A genus of toads. 



Byssus. A thread attached near the adductor muscle of a glochidium ; or a bunch of 

 threads attached to the foot of certain clams. 



Caecilian. One of a group of legless, wormlike Amphibia of the order Apoda. 



Caecum (see' kum). The blind pouch at the beginning of the large intestine. 



Calcarea. A class of sponges (Porifera) whose skeletons are composed of spicules 

 of calcium carbonate. 



Calciferol [kal sif er ole). Vitamin D, the preventive of rickets. 



Calorie (kaV o ri). The quantity of heat required to raise the temperature of a kilo- 

 gram of water 1°C.; this is a large calorie, equal to 1000 small calories. 



Cambrian (kam' bri an). Of the earliest Paleozoic time. 



Camponotus. A genus of ants. 



Canaliculus (kan' a lik' u lus). One of numerous minute channels radiating from 

 each lacuna in the matrix of bone, in which slender processes of the bone cells 

 are located. 



Cancellate {kan^ set late). Composed of a number of chambers separated by parti- 

 tions; said of spongy bone. 



Canine (ka' nine). A tooth located laterally to the incisors. 



Capillary. One of numerous small vessels conveying blood through the tissues from 

 arteries to veins or from one vein to another. 



Carapace. The hard bony covering of a turtle; also the chitinous or calcareous cover- 

 ing of the cephalothorax of a crayfish or lobster. 



Carbohydrate. Any one of a class of organic substances, embracing the starches, 

 sugars, cellulose, etc., which are composed of carbon, hydrogen, and oxygen, 

 with the number of atoms of hydrogen and oxygen regularly in the ratio 

 of 2:1. 



Carboniferous. The geological age to which the principal known coal beds belong; 

 succeeding the Devonian, it is a combination of Mississippian and Pennsylvanian. 



Carchesium (kar ke' zi %im). A genus of colonial ciliated Protozoa, resembling 

 Vorticella. 



Cardiac. Pertaining to or near the heart. 



Carnivore. Technically, a mammal of the order Carnivora, including the cats, dogs, 

 and seals. In a popular sense, any flesh-eating animal. 



Carnivorous. Flesh-eating. 



Carotene. A yellow pigment found in carrots and many green or yellow vegetables; 

 a source of vitamin A. 



Carpal. One of a number of bones in the wrist in vertebrates. 



