MUSTELIDE 581 
compressed ; first and second subequal, third considerably larger. 
Lower incisors very small, especially the first, and crowded 
together, the second placed rather behind the others. Canines 
long and sharp-pointed. Upper premolars: first very small, with 
simple crown and one root; second and third nearly equal in size 
and two-rooted, with simple compressed sharp-pointed crowns, 
with very slightly developed accessory cusps; fourth (the carnassial) 
with blade consisting chiefly of the central and posterior lobes, the 
anterior being rudimentary, inner tubercle small and confined to 
the anterior part of the tooth. True molar tubercular, about 
twice as wide transversely as in the antero-posterior direction, 
having an outer, more elevated, but smaller portion, bearing three 
blunt tubercles ; to the inner side of this the crown is contracted, 
and its surface deeply hollowed; it then expands again into a 
broad low lobe, with the central part elevated, and a raised, even, 
semicircular, slightly crenated internal border. Lower premolars : 
first very small, simple, and one-rooted ; second, third, and fourth 
increasing slightly in size, with high compressed pointed crowns 
and posterior accessory cusps, best marked in the third. First 
molar (carnassial) with well-marked bilobed blade, talon scarcely 
more than one-third of the length of the tooth, and a very small 
inner cusp. Second molar small, single-rooted, with a low, 
flattened, subcircular or oval tubercular crown. 
In geographical distribution the Martens are limited to the 
northern hemisphere, ranging throughout the greater part of the 
temperate regions of both Old and New Worlds, as far north as 
conditions of existence suited to their habits are met with, and 
southwards in America to 35° N. lat., while in Asia one species is 
met with as far in this direction as the island of Java. 
The various species appear to be very similar in their habits. 
They live in woods and rocky places, and are thoroughly arboreal, 
spending most of their time in trees, although descending to the 
ground in quest of prey. They climb with great facility, and are 
agile and graceful in their movements. Some species are said 
occasionally to resort to berries and other fruit for food, but as a 
rule they are strictly carnivorous, feeding chiefly on birds and their 
eges, small mammals, as squirrels, hares, rabbits, and moles, but 
chiefly mice of various kinds, of which they destroy great numbers, 
and occasionally snakes, lizards, and frogs. In proportion to their 
size they are among the most bloodthirsty of animals, though less 
so than the true Weasels. The female usually makes her nest of 
moss, dried leaves, and grass in the hollow of a tree, but sometimes 
in a hole among rocks or ruined buildings, and produces several 
young at a birth, usually from four to six. Though wild and 
untameable to a great degree if captured when fully grown, when 
taken young they are very docile, and have frequently been made 
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