400 UTILITARIAN ZOOLOGY 



hard metallic -looking wing-covers or elytra of certain Beetles 

 serve for various decorative purposes, and some of the more 

 beautiful Butterflies are sometimes placed in glass cases and used 

 as ornaments. Some of the Scale- Insects (Coccida) are the 

 source of economic products of some importance in the present 

 connection, e.g. the Cochineal Insect (Coccus cacti) furnishes red 

 pigment (see p. 260). Objects known a " ground pearls" are 

 found in the earth in various parts of the world, e.g. in the island 

 of St. Vincent (West Indies), where they are made into neck- 

 laces, &c. They are in reality the encysted pupae of Scale- 

 Insects, covered by a hard substance looking like pearl or 

 glass. The West Indian ones mentioned above belong to a 

 species of Margarodes. 



ANIMAL AESTHETICS 



The course of human evolution has necessarily involved a 

 gradually improving adaptation to surroundings, of which the 

 outcome is seen in all the intricate details of modern civilization. 

 Imaginative literature and the various branches of art are 

 among the most remarkable results of this evolution, and the 

 full discussion of their nature and origin is the province of that 

 branch of philosophy known as /Esthetic. But as, after all, 

 man is an animal, who has always lived among other animals 

 that have profoundly influenced the course of his mental de- 

 velopment, it naturally follows that the study of /Esthetic, as 

 indeed of all other departments of philosophy, must look for its 

 foundations among the principles of biology. The interdepend- 

 ence of natural science and philosophy is well brought out in the 

 following quotation from Karl Groos (in The Play of Animals}' 

 " Man's animal nature reveals itself in instinctive acts, and the 

 latest investigators tell us that man has at least as many instincts 

 as the brutes have, though most of them have become unrecog- 

 nizable through the influence of education and tradition. There- 

 fore an accurate knowledge of the animal world, where pure 

 instinct is displayed, is indispensable in weighing the importance 

 of inherited impulses in men. . . . The animal psychologist must 

 harbour in his breast not only two souls, but more; he must 

 unite with a thorough training in physiology, psychology, and 

 biology the experience of a traveller, the practical knowledge of 



