burroughs] PROTECTIVE COLORS OF ANIMALS 159 



silk and soaking' the cocoon a few minutes in hot water, per- 

 mitting- the thread to be loosened with a pin. 



Any one expecting to rear the silk insect should request the 

 I nited States Department of Agriculture, Washington, D. C, to 

 send him Farmers' Bulletin Xo. 165, by H. A. Kelly. It is free. 



The value of the silk-worm for nature-study work cannot be 

 overestimated. The pupils may be taught so effectively the im- 

 portant lesson of how life responds to the patience and care 

 bestowed upon it. They may witness the transformation of vege- 

 table material into animal tissue and be brought into intimate 

 association with the indirect process by which mother earth is 

 transmuted into the most beautiful of fabrics. A contact point 

 is secured for giving a lesson teaching the miserable condition of 

 the lower classes in Italy, China and Japan where silk-worm 

 raising can be carried on commercially because of the starvation 

 wages accepted by the peasants. The interesting history of the 

 origin and spread of the silk industry may give the child a yearn- 

 ing to know more of oriental life. The four stages in the devel- 

 opment of the insect are the same as those occurring in about 

 half the species of the animal kingdom and the remarkably quick 

 changes in the external features of the animal prevent the pupil 

 from losing interest in his study. Moreover abundant oppor- 

 tunity is afforded for cultivating the powers of observation and 

 expression in sketching and describing the numerous phases of 

 growth. 



PROTECTIVE COLORS OF ANIMALS 



Review of an article by John Burroughs 



Attempts at explaining the uses and meaning of natural objects 

 and processes are much more common in nature-study teaching 

 than in elementary science of high schools and colleges, and it is 

 common to find teachers and pupils in search of a use for every- 

 thing. Perhaps no phase of nature has been the subject of so 

 much attempted explanation as has color, particularly that of 

 animals and of plants in relation to animals. Accepting almost 

 unreservedly the Darwinian hypothesis that colors of many ani- 

 mals play an important part in the life-and-death struggle, we 

 have grown accustomed to finding some correspondence between 

 the color of an animal and that of its environment. We have 



