318 GLOSSARY. 



flower. They are usually of delicate texture and brightly 

 coloured. 



Phyllodineous. — Having flattened, leaf-like twigs or leafstalks 

 instead of true leaves. 



Pigment. — The colouring material produced generally in the super- 

 ficial parts of animals. The cells secreting it are called piyment- 

 cells. 



Pinnate. — Bearing leaflets on each side of a central stalk. 



Pistils. — The female organs of a flower, which occupy a position 

 in the centre of the other floral organs. Tlie pistil is generally 

 divisible into the ovary or germen, the style and the 

 stigma. 



Placentalia, Placentata, or Placental Mammals. — See Mam- 

 malia. 



Plantigrades. — Quadrupeds which walk upon the whole sole of 

 the foot, like the Bears. 



Plastic. — Eeadily capable of change. 



Pleistocene Period. — The latest portion of the Tertiary epoch. 



Plumule (in plants). — The minute bud between the seed-leaves of 

 newly-germinated plants. 



Plutonic Rocks. — Rocks supposed to have been produced by 

 igneous action in the depths of the earth. 



Pollen. — The male element in flowering plants ; usually a fine dust 

 produced by the anthers, wliich, by contact with the stigma 

 efi'ects the fecundation of the seeds. This impregnation is 

 brought about by means of tubes (polhn-tuhes) which issue 

 from the pollen-grains adhering to the stigma, and penetrate 

 through the tissues until they reach the ovary. 



PoLYANDROUS (flowers). — Flowers having many stamens. 



Polygamous Plants. — Plants in which some flowers are unisexual 

 and others hermaphrodite. The unisexual (male and female) 

 flowers, may be on the same or on different plants. 



Polymorphic. — Presenting many forms. 



PoLYZOARY. — The common structure formed by the cells of the 

 Polyzoa, such as the well-known Sea-mats. 



Prehensile. — Capable of grasping. 



Prepotent. — Having a superiority of power. 



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

 inserted upon that part wliich represents the hand of man. 



Peocesses. — Projecting portions of bones, usually for the attach- 

 ment of muscles, liijaments, &c. 



