320 GLOSSARY. 



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

 and Squirrels. They are especially characterised by the pos- 

 session of a single pair of chisel-like cutting teeth in each 

 jaw, between which and the grinding teeth there is a great 



gap- 



RuBUS. — 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. 



Saceal. — Belonging to the sacrum, or the bone composed usually 

 of two or more united vertebriE to which the sides of the pelvis 

 in vertebrate animals are attached. 



Sarcode. — The gelatinous material of which the bodies of the 

 lowest animals (Protozoa) are composed. 



ScuTELL^. — The horny plates with which the feet of birds are gen- 

 erally more or less covered, especially in front. 



Sedimentary Formations. — Rocks deposited as sediments from 

 water. 



Segments. — The transverse rings of which the body of an articulate 

 animal or Annelid is composed. 



Sepals. — The leaves or segments of the calyx, or outermost enve- 

 lope of an ordinary flower. They are usually green, but some- 

 times brightly coloured. 



Serratuees. — Teeth like those of a saw. 



Sessile. — Not supported on a stem or footstalk. 



SiLUEiAN System. — A very ancient system of fossiliferous rocks 

 belonging to the earlier part of the Palseozoie series. 



Specialisation. — The setting apart of a particular organ for the 

 performance of a particular function. 



Spinal Chord. — The central portion of the nervous system in the 

 Vertebrata, which descends from the brain through the arches 

 of the vertebrae, and gives oil nearly all the nerves to the va- 

 rious organs of the body. 



Stamens. — The male organs of flowering plants, standing in a circle 

 within the petals. They usually consist of a filament and an 

 anther, the anther being the essential part in which the pollen, 

 or fecundating dust, is formed. 



Sternum. — The breast-bone. 



Stigma. — The apical portion of the pistil in flowering plants. 



