288 LECTURE VI. 



The hairs are sometimes straight, and 

 sometimes curved or waving, and when of 

 the latter kind they intermix and form a 

 fleece. In birds and beasts the stronger 

 hairs and feathers make an external coat, 

 and beneath this we find a downy or furry 

 vestment of the same parts, but of a more 

 delicate, structure. 



These garments of animals are, from their 

 texture, bad conductors of heat, and well 

 calculated to prevent external heat or cold 

 from affecting the animal temperature. 



The garments of animals also exclude 

 moisture from being oiled, either by unc- 

 tuous fluids transuding from the skin, or 

 from their being applied by the voluntary 

 act of the animal ; Nature having given 

 to birds in common, and particularly to 

 those that are aquatic, as well as to many 

 animals, oil-bags for that purpose. 



The coverings of many animals seem 

 merely designed for theii; defence, as the 

 shells of tortoises, armadillos, and the scales 



