4i8 BIOLOGY AND HUMAN LIFE 



Fabrics made from the hairs of other animals are not of great 

 importance, but the furs of many mammals are important not 

 only commercially but because they supply warm garments for 

 millions of people who are exposed to cold weather. Bristles 

 and other hairs are of value in the making of brushes of all 

 kinds. The hides of animals supply the staple leather for most 

 of our shoes and for belting, luggage, gloves, and so on. Most 

 of our leather comes from the skins of mammals, but alHga- 

 tors and other reptiles have furnished valuable leathers, and the 

 skins of various sharks have been used. 



Related to the hairs of mammals are the feathers of birds, 

 which have their chief practical use in the stuffing of pillows 

 and as ornaments. Quills formerly served as writing pens, but 

 they have been almost entirely replaced by metal pens. 



Most of us recognize fibers in the many different forms in 

 which they are used, but most of us do not know that paper 

 and the transparent film used in motion pictures are derived 

 from plant fibers. Some of the finest paper is made of linen 

 fibers in old linen rags ; but most of the paper, of which millions 

 of tons are consumed every year, is made of the cheaper fibers of 

 wood. Hundreds of acres of forests are consumed every week to 

 supply stock for the daily newspapers alone. Celluloid for pho- 

 tographic films and other articles is made of the best quality 

 of cotton. Methods are being developed for utilizing cheaper 

 fibers, such as wood, for some grades of celluloid or substitutes. 



In different parts of the world the straw fibers of many plants 

 have been used to some extent for clothing, but chiefly for rugs, 

 mats, screens, furniture covers, and similar articles. The coco- 

 nut fiber, called coir, which we see chiefly in the form of door- 

 mats, comes from the husk covering the fruit of the coconut 

 (see Fig. 179). It is used extensively for cordage where the 

 coco palm is common. 



310. Shelter. From clothing to shelter is a logical step, since 

 clothing is the kind of shelter that we carry around with us, 

 whereas a house is the kind of shelter that usually remains in a 

 fixed place. Since the purpose of the two is very much the same, 



