GLOSSARY. 267 



Carpodite. The fifth joint of the leg of a Crustacean. 



Cell. (1) In its original condition " a naked lump of protoplasm 

 with an imbedded nucleus," and with or without an external 

 membrane. (2) The interneural spaces in the wings of insects. 



Cellulose. A peculiar substance forming the cell- wall of plants ; 

 it is found also in the tests of the Ascidioida. 



C&nogenesis. Embryonic adaptation. 



Central capsule. A porous membrane separating the sarcode of 

 the Radiolarians from the " yellow cells." 



Centrum. The body or common centre of a vertebra. 



Ceratode. The horny substance of sponges. 



Cercarics. The tadpole-like larvas of the Trematode worms and 

 of many Ascidians. 



Cerci. Setaceous or filiform appendages attached to the last seg- 

 ment of the abdomen in certain Orthoptera. 



Cere. The naked skin at the base of the bill in some birds. 



Cerebellum. The posterior portion of the brain. 



Chelcs. The " claws " or anterior pair of thoracic legs of the 

 Crustaceans, generally of large size and furnished with two 

 " fingers," only one of which is movable. 



ChelicercB. The prehensile " pincer-ended " claws placed on each 

 side of the mouth of scorpions. They are supposed to be mo- 

 dified antennae. 



Chevron-bones. Small bones placed below and between the caudal 

 vertebrae and protecting the artery. 



Chiasma. The expansion formed by the union of the optic nerves-* 



Chitine. The substance composing the exoskeleton of insects. 



Chlorophyll. The green colouring-matter of leaves, found also 

 in the Infusoria, Turbellaria, &c. 



Choance. The nasal cavities. 



Chondrine = gristle. 



Chorda dorsalis. See Notochord. 



Chorion. The outer membrane of the ovum. 



Chorology. The study of the local distribution of animals over 

 the earth. 



Chromatophores. Minute sacs containing pigmentary matter. 



Chyle. A milky fluid, the nutrient portion of the food. 



Chyme. The digested food as it passes from the stomach. 



Cicatricula or "tread," a peculiar opaque spot on the embryo. 



