Ti)e 3q,airreis and Otfyer Kpdenis; 

 of tbjz Adirondack 



By Frederick C. Paulmier.* 



EXCEPT for the comparatively few domesticated animals, which include the 

 horses and cattle, belonging to the Ungulata, or grazing animals, and 

 the carnivorous cats and dogs, by far the greater number of those which 

 come into economic relations with man belong to the order Rodentia, or the 

 gnawing mammals. In distinction, however, from the domesticated forms, which 

 are used as food, or as beasts of burden, or as companions, the Rodentia are 

 nearly all injurious, only in a very limited degree serving man as food or furnish- 

 ing him with useful skins. True it is that some forms are hunted, and noted 

 apologists for this form of sport are not wanting. Still, when the balance is 

 struck, it is found that the misdeeds of some of them many times counterbalance 

 what value the rest of them possess. 



Scientifically speaking, the Rodentia may be described as mammals in which 

 the number of teeth is reduced, the back teeth, or molars and premolars, varying in 

 number from four to six on each half of the jaw, and with the eye teeth, or canine 

 teeth, always wanting. It is in the front, or incisor teeth, however, that the greatest 

 modifications occur, for they are specially adapted for gnawing, and to this end 

 have only the front edge composed of hard enamel, while the back part is composed 

 of softer dentine, which, wearing away more rapidly than the harder enamel, 

 under the constant use that the teeth are put to, leaves a sharp, chisel-like edge 

 to the latter. To compensate for this wear, which would soon bring the teeth 

 down to the gums, these teeth, unlike other mammal teeth, grow continuously 

 at the base, throughout the life of the animal, at a rate which just compensates 

 for the loss at the tip. Should, however, as sometimes happens, one of these 

 front teeth become broken or lost so that its fellow in the opposite jaw has nothing 

 to wear against, and by that be kept short, the latter grows to an inordinate 

 length, usually curving around into the mouth of the animal and killing it, either 

 by preventing it taking food or by growing through the roof of the mouth into 

 the brain. 



* Zoologist, Division of Science, N. Y. State Museum. 



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