THE GOPHER TORTOISE. 5 



vertebrate animals, the portion which represents the true shoulder-blade being almost 

 cylindrical, one of the branches flattened, and the other cylindrical, but larger than the 

 real blade-bone. This structure admits of the attachment of powerful muscles, and 

 gives to the fore limbs the great strength which is needed for digging, swimming, climb- 

 ing, and various modes of exertion. The strong curved bones of the fore limbs bear 

 an evident analogy to the corresponding parts in the mole, with its powerful claws and 

 feet, and its very long blade-bone. 



The horny substance commonly termed " tortoiseshell," which is spread in flattened 

 plates on the exterior of the bony case, is thought to be a modification of the scales 

 found on lizards, serpents, etc., and which exist on the legs and other parts of the 

 Tortoises themselves. The row of horny pieces which are found on the edge of the 

 carapace also belong to the " dermal skeleton." 



The Tortoises are quite devoid of teeth, the edge of the jaws being sharp and horny, 

 so as to inflict a severe wound ; and in many species one or both jaws are sharph/ 

 hooked at the tip like a falcon's beak. The neck is always rather long, and in many 

 species can be protruded to a considerable extent. Generally, the process of thrusting 

 the neck from the shell is a slow one, but the withdrawal is accomplished with marvel- 

 lous rapidity, on account of certain long muscles which tie the neck to the back of the 

 carapace. Possibly these muscles, together with their tendons, would, when dried in 

 the baking sunshine, produce musical sounds when touched, and thus give rise to the 

 old poetical legend of the origin of the lyre. 



The brain of the Tortoise is very small in proportion to the size of the animal ; in the 

 turtle weighing not quite one five-thousandth part of the whole body, and in the land 

 Tortoise about one two-thousandth part. In man the brain is about one fortieth the 

 weight of the body. 



The Tortoises produce their young from eggs, mostly soft and leathery in the text- 

 ure of their covering, which are laid in some convenient spot, and left to be hatched 

 by heat not derived from the parent. The circulation in the Tortoise is not very com- 

 plete, but the arterial blood is redder and brighter than the venous. 



I\ the true TORTOISES the feet are club-shaped and the claws blunt, and the neck 

 can be wholly withdrawn within the shell. 



The first example of these creatures is the GOPHER, or MUNGOFA TORTOISE, a native 

 of America. This is a rather pretty, though not brightly colored species, its shell 

 being mostly brownish yellow, boldly and variously clouded with rich dark brown. 

 The lower jaw is yellow, and the whole of the plastron is yellow-brown. It is found 

 plentifully in Georgia and Alabama, but according to Mr. Holbrook is not seen farther 

 north than South Carolina. When full grown it is a moderately large species, from 

 thirteen to more than fourteen inches in length, and very convex. The following 

 interesting account of its habits is given by Mr. Holbrook in his valuable " North 

 American Herpetology : " 



" They select dry and sandy places, are generally found in troops, and are very 

 abundant in pine-barren countries. They are gentle in their habits, living entirely on 

 vegetable substances. They are fond of the sweet potato (Convolvulus batatas], and at 

 times do much injury to gardens by destroying melons, as well as bulbous roots, etc., 

 etc. In the wild state they are represented as nocturnal animals, or as seeking their 

 food by night : when domesticated and I have kept many of them for years they 

 may be seen grazing at all hours of the day. 



When first placed in confinement, they chose the lowest part of the garden, where 

 they could most easily burrow. This spot being once overflowed by salt water in a 

 high spring-tide, they migrated to the upper part, nearly eighty yards distant, and pre- 

 pared anew their habitations. They seldom wandered far from their holes, and gen- 

 erally spent part of the day in their burrows. They delighted in the sun in mild 

 weather, but could not support the intense heat of our summer noons ; at those 

 hours they retreated to their holes, or sought shelter from the scorching rays of 

 the sun under the shade of broad-leaved plants. A tanyer (Arum esculcntnm'} 

 that grew near their holes was a favorite haunt. They could not endure rain, 



