AVES 301 



18. Psittaci. Parrots. 



19. CoccygomorphcB. Cuckoo. 



20. Pici. Woodpeckers. 



21. Cypstiomorphce. Whip-poor-will, bull bat, humming birds. 



22. Passeres. The song birds; a very large order. 



Sub-order i. Clamatores. King bird. 



Sub-order 2. Oscines. Swallows, fly catchers, warblers, thrushes, 

 black birds, mocking bird, cat bird, larks, titmouse, crows, ravens, 

 finches, sparrows. 



651. Class VI. Mammalia. — The Mammals are typically 

 covered with hair. In several cases the hairs are scattered or 

 limited to the ^^ whiskers" as, e. g., in some marine mammals — 

 the sea cow and whale. The function of the hair is primarily 

 to retain the heat of the body. When the hair is wanting the 

 function may be performed by a thick layer of fat beneath the 

 skin. The name mammal refers to the mammary glands in 

 the skin of the ventral surface of the body. There are usually 

 two sets of teeth, first a milk dentition which is later replaced 

 by a permannt dentition. The latter consists of four kinds, 

 incisors, canines, pre-molars and molars. The heart consists 

 of four chambers; the red blood corpuscles are without a 

 nucleus; the temperature of the body is constant. The lungs 

 and heart are separated from the abdominal viscera by a muscu- 

 lar membrane, the diaphragm, which thus divides the body 

 cavity into thoracic and abdominal cavities. There is no 

 cloaca, the vent and the openings of the urino-genital systems 

 are separate. The eggs are fertilized in the oviduct and develop- 

 ment continues for a variable period, up to two years in the 

 elephant, in an enlargement of the oviduct called the uterus. 

 The embryo is provided with the foetal membranes, amnion 

 and allantois. The sense organs are usually highly developed 

 and the brain, especially the cerebral and cerebellar parts, is 

 much in advance of those of all other animals. 



652. The thirteen orders belong to three sub-classes as follows: 

 Sub-class Monotremata. Spiny ant-eater, duck mole. 



