such mastery of flight that it does not trouble to swerve until it is almost 

 upon an object, so that at times it appears to be coming directly at one. 

 "Blind as a bat" is a poor figure of speech, for bats have small but fully func' 

 tional eyes. If plenty of space and insect food are available, one or two 

 bats make interesting pets and soon learn to take moths or grubs from the 

 keeper's fingers. They must be given opportunity for flying exercises, to remain 

 healthy. If their keeper has keen ears, he may be able to distinguish the very 

 high-pitched squeaking they make as they fly, and which, bouncing back to their 

 highly specialized ears, enables them to avoid obstructions. This use of "sonar" 

 has been demonstrated at the Massachusetts Institute of Technology, where the 

 sounds have been electrically transformed into lower tones more audible to 

 human ears. 



Few people realize that each year the United States still produces mib 

 liens of dollars worth of valuable furs. The beaver, the demand for whose 

 beautiful and durable fur was one of the factors leading to the settlement of 

 North America, has unfortunately been extremely reduced in numbers, but 

 its little brother, the muskrat, has taken its place as America's most valuable 

 fur bearer. Mink, weasel, skunk, fox, raccoon and others all help swell the 

 total. Unfortunately there has often been antagonism and distrust between 

 trapper and naturalist. The upset in the balance of nature in cases where 

 well-meaning but poorly informed voters have practically prohibited trapping 

 has shown that the trapper plays a useful part, taking the place once occupied 

 by wolf, wildcat, eagle and hawk. The cruelty of steel traps has been con- 

 siderably over-emphasized. If traps of the right sizes are used, properly at- 

 tached so that an animabs first jump does not bring it up with a jerk, and if 

 traps are visited each morning and evening, there is a minimum of suffering. 

 Also it should be remembered that, with the exception of the muskrat (and 

 even it enjoys clams and fish), all of our best fur bearers are carnivores, 

 which, if not kept in check, will multiply sufficiently to bring many other 

 mammals and birds to the point of extinction. The regulation of trapping 

 should be undertaken on the advice of game wardens and field zoologists, 

 whose training enables them to see the practical solutions, rather than on 

 the opinions of sentimentalists or those who may profit by the exploitation 

 of wild life. 



It is highly desirable that every naturalist should know how to make up 

 a study skin of a mammal. Sometimes rare or unusual material comes to 

 him unexpectedly and valuable specimens may spoil unless given prompt at- 

 tention. A study skin is the coat of a mammal preserved and poisoned against 

 insect pests and filled out to approximately its normal size and contours. The 

 work is easily learned and, if desired, the mammal may later be mounted in 

 a hfelike attitude by a professional taxidermist. Before skinning the animal 

 at least two careful measurements should be made, of (1) total length — 



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