SQUIRRELS. 257 



they reach, their minimuin. This is very strikingly seen in the Common Deer, which on the Sea 

 Islands of Georgia is so small as to be readily lifted and thrown across a horse with perfect ease by 

 a man of ordinary strength. It is in the Sciurida;, next to the Deer, we find this law to prevail 

 m^ost decidedly. Nearly all the species of extensive North and South range will be found, on careful 

 examination, to substantiate this position." 



It ajjjjears also that, as with the Foxes, the smaller species of Squirrel assmne the black fur 

 to the greatest extent in the more northern portions of the United States. Dr. Baird also made 

 this observation, that as a general rule where a Squirrel exhibits any annulation of the fur on the 

 throat or belly, it is a variety of some species, typiical examples of which have the imder parts 

 either imiformly white or reddish to the roots, and the annulation is usually accompanied by a 

 duskier coloui- of the fur. The tendency to amiulation below is strongest in the Squirrels of the 

 Mississippi Valley, and applies both to grey and fox-coloiu'ed species. But Dr. Baird had met 

 with no instances of annulation among the Squirrels west of the Rocky Mountains. 



There is another cui'ious pecidiarity in some of the North x\jiicrican Squirrels, which may give 

 a hint for testing varieties or species in other instances. It illustrates the proverb " that what is 

 bred in the bone will come out in the flesh ; " here it should be " the fur." The bones of the Fox 

 Squii-rels, which have rusty-coloured bellies, are red ; those of the white-bellied varieties are white. 

 This is not an isolated case of colour penetrating to the bones. A variety or species of domestic 

 fowl has always black bones. 



Flying Squirrels. These are divided into two sections, readily distinguishable, the one by 

 having the fur of its tail divided distichously, and smoothed off to each side (Sciuroi'terus) ; the otlier 

 (Pteromys) by the tail being bushj' all round. Both have their representatives in the Marsujjial 

 Petavrt and Acrobata, in Australia the former corresponding to Pteromj's, the latter to Sciuropterus. 



SciUROPTERUS. (Map 94.) This section has much the same distribution as the true Squirrels, — 

 that is, the preponderance of species inhabits the Indian Archipelago, — then about a third of the 

 whole are North American, and a single species (Sc. volans) is found in north-cast Europe and 

 north-west Siberia, not extending eastwards beyond the Lena. There are fifteen species in all. 

 According to Audubon, the Sciuropterus volucella is far more numerous in North America than 

 it is supposed to be. He frequently caught it in traps set for the smaller Rodentia in localities 

 where he had never seen it.* It is met with in all the Atlantic States, and Audubon obtained 

 specimens in Upper Canada, within a mile of the Falls of Niagara. But there is reason to bcKeve 



* I can readily imagine this. With permission of the hundred of them every evening for several weeks near 



authorities I once turned loose a living specimen of this Philadelphia, on two tall oaks, in the autumn when acorns 



American species into the large palm-house in the Eoyal and chestnuts were abundant, and when they had spare 



Botanic Gardens, Edinburgh. The moment it was released time to play. They were amusing themselves by passing 



from its little cage, it flew up the nearest tree like a shot. from one tree to another, throwing themselves oif from the 



We saw it for a short time, high up, clasped to the truuk, top of one of the oaks and descending at a considerable 



until it made another dart, when it vanished from our angle to near the base of the other ; then inclining the 



sight; and the eager searching of many keen eyes was ever head upwards just before reaching the gi'ouud, so as to 



after unavailing to obtain a glimpse of it. Sir Charles turn and alight on the trunk, which they immediately 



Lyell bears similar testimony. He tells us that at Charles- climbed up to repeat the .same manoeuvre. In this way 



ton he expressed his regret to Dr. Bachman that he had there was an almost continuous flight of thein crossing 



not yet seen the Flying Squirrel in motion, " and was sur- each other in the air between the two trees." — Lvell's 



prised to hear that Dr. Bachman had observed about a " Second A^'isit to the United States," vol. i. 303. 1850. 



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