GLOSSARY. 439 



Primaries. — The feathers forming the tip of the wing of a bird, and in- 

 serted upon that part which represents the hand of man. 



Processes. — Projecting portions of bones, usually for the attachment of 

 muscles, ligaments, &c. 



Propolis. — A resinous material collected by the Hive-Bees from the 

 opening buds of various trees. 



Protean. — Exceedingly variable. 



Protozoa. — The lowest great division of the Animal Kingdom. These 

 animals are composed of a gelatinous material, and show scarcely any 

 trace of distinct organs. The Infusoria, Foraminifera, and Sponges, 

 with some other forms, belong to this division. 



Pupa (pi. Pup.e). — The second stage in the development of an Insect, from 

 which it emerges in the perfect (winged) reproductive form. In most 

 insects the pupal stage is passed in perfect repose. The chrysalis is the 

 pupal state of Butterflies. 



Radicle. — The minute root of an embryo plant. 



Ramus. — One half of the lower jaw in the Mammalia. The portion which 

 rises to articulate with the skull is called the ascending ramus. 



Range. — The extent of country over which a plant or animal is naturally 

 spread. Range in time expresses the distribution of a species or group 

 through the fossiliferous beds of the earth's crust. 



Retina. — The delicate inner coat of the eye, formed by nervous filaments 

 spreading from the optic nerve, and serving for the perception of the 

 impressions produced by light. 



Retrogression. — Backward development. When an animal, as it ap- 

 proaches maturity, becomes less perfectly organised than might be 

 expected from its early stages and known relationships, it is said to 

 undergo a retrograde development or metamorphosis. 



Rhizopods. — A class of lowly organised animals (Protozoa), having a gela- 

 tinous body, the surface of which can be protruded in the form of root- 

 like processes or filaments, which serve for locomotion and the prehen- 

 sion of food. The most important order is that of the Foraminifera. 



Rodents. — The gnawing Mammalia, such as the Rats, Rabbits, and 

 Squirrels. They are especially characterised by the possession of a 

 single pair of chisel-like cutting teeth in each jaw, between which and 

 the grinding teeth there is a great gap. 



Runus. — The Bramble Genus. 



Rudimentary. — Very imperfectly developed. 



Ruminants. — The group of Quadrupeds which ruminate or chew the 

 cud, such as oxen, sheep, and deer. They have divided hoofs, and are 

 destitute of front teeth in the upper jaw. 



Sacral. — Belonging to the sacrum, or the bone composed usually of two 



or more united vertebrae to which the sides of the pelvis in vertebrate 



animals are attached. 

 Barcode. — The gelatinous material of which the bodies of the lowest 



animals (Protozoa) are composed. 

 SCDTELLiE. — The horny plates with which the feet of birds are generally 



more or less covered, especially Ln front. 

 "Sedimentary Formations. — Rocks deposited as sediments from water. 



