86 



LEAVES FROM THE NOTE-BOOK OF A NATURALIST. 



a much quicker inarch on land, leading a preda- 

 tory, quisquilious, amphibious life, and frequenting 

 sluggish streams, the lake, the pond, and the 

 marsh Their food consists principally of fresh- 

 water molluscous animals, tailless and tailed 

 batrachians,* and annelids, or worm-like crea- 

 tures. 



The honeymoon of these elodians endures for 

 many weeks at a certain time of the year ; and 

 their prolonged loves are blest with a goodly batch 

 of spherical eggs, without any calcareous shell, 

 but as white as those of the other chelonians. 

 The nest is a shallow cavity in the earth, scraped 

 out by the female ; and the banks of the waters, 

 wherein she spends much of her time, are general- 

 ly selected ; for her instinct teaches her that such 

 a locality offers a refuge to the young, who take 

 refuge in the waters from their numerous enemies 

 as soon as they are hatched. 



And here it may be observed that the Chersians, 

 or land-tortoises, are, as a general rule, feeders on 

 vegetables ; the Thalassians, or sea-tortoises, 

 commonly known as turtles, both vegetarian (in 

 some cases almost entirely so) and carnivorous ; 

 while the Elodians, or marsh-tortoises, and the 

 Potamians, or river-tortoises, which may both be 

 classed under one common head, the gradation 

 being almost insensible, are supported on animal 

 food, the prey being generally taken in a living 

 state. In conformity with this dispensation, the 

 anterior extremity of the upper bill in the majority 

 of species exhibits a large notch, and on each side 

 of it a sufficiently strong tooth, reminding the ob- 

 server of the beak of the higher raptorial birds. 



In some of this group, Nature, which in the 

 chelonian forms which we have already noticed 

 had contented herself with a lid either before or 

 behind, carries out what may be termed the box 

 principle, by making, as in the genus Cistudo, a 

 movable lid both before and behind. In this sub- 

 genus a cartilage attaches the wide oval plastron 

 to the buckler. This cartilage is movable both 

 before and behind, turning on the same transversal 

 mesial hinge, and, at the will of the animal, pre- 

 senting nothing but a well-closed box to the pry- 

 ing eyes of the enemy. In Kinosternon, also, the 

 oval sternum is movable before and behind on a 

 fixed piece ; but in Staurotypus, the thick cruci- 

 form sternum is movable in front only. In others 

 again, Platysternon and Emysaura, for example, 

 the plastron is immovable. 



The Potamians, or true river-tortoises, whose 

 species have been confounded under the name of 

 Trionyx, have among them some which grow to a 

 considerable size. To say nothing of one which 

 was kept by Pennant, and weighed twenty pounds, 

 seventy pounds have been stated as the weight 

 attained by certain individuals. Inhabiting the 

 streams and rivers, or great lakes of the warmer 

 regions of the earth, their habits are generally 

 similar. Swimming with much ease either upon 

 or beneath the surface of the water, they pursue 



* Anurous and urodcle batrachians of the learned. 



roung crocodiles, other reptiles and fishes, which 

 heir agility enables them to make their prey. 

 They are also said to be great destroyers of the 

 ;ggs of the crocodiles, especially in the Nile and 

 he Ganges. The angler baits his hook for them 

 with small fishes or other living bait, unless his 

 skill enables him so to play a dead or artificial one 

 as to deceive the sharp eyes of these tortoises, 

 whose flesh is considered very good for the table. 

 .f he goes out with proper tackle, the sport is 

 satisfactory enough ; but one of them took the fly 

 of a justly-celebrated singer and skilful disciple of 

 old Izaak's school, while he was fishing for trout. 

 Ele thought he had got hold of an old boat ; but, 

 unwieldy as his prize was, he would probably 

 lave landed it if left to himself. His stupid at- 

 tendant, however, rushed forward and seized the 

 .ine, which, thus deprived of the spring of the rod, 

 :ould not bear the strain, and the potamian got 

 lear off. 



Islets, rocks, floating timber, or the trunks of 

 "alien trees on the banks, are the favorite places 

 of resort to which these tortoises come for repose 

 during the night. But they are very wary, and 

 the least noise sends them immediately into the 

 water. They are troublesome customers to those 

 who are not aware of their mode of attack. When 

 they seize their prey, or are on the defensive, they 

 suddenly and most rapidly dart out their retracted 

 tiead and long neck, like lightning, biting most 

 sharply ; and rarely relaxing their hold till they 

 have taken the piece, into which they have fixed 

 their cutting and pertinacious bill, out. The 

 fisherman, therefore, either cuts off their heads as 

 soon as he has secured them, or reins them up 

 with a sort of bridle, so as to prevent the dreaded 

 bite ; and, in this last state, I have been told, they 

 are often exposed alive for sale in the markets. 



In the months of April or May, the sandy spots 

 on the banks of the rivers or lakes which have a 

 good exposure to the sun are sought out by the 

 females, as the places of deposit of their eggs, to 

 the amount of some fifty or sixty ; and in July the 

 young make their appearance. The patience of a 

 German is proverbial ; with the eternal pipe in his 

 mouth, he calmly follows out his subject, and fol- 

 lows it out well ; but when we find Monsieur 

 Lesueur patiently counting the ova in the ovary 

 of a potamian mother, and deliberately giving the 

 results, we pause, and thank the gods who have 

 disposed the mercurial mind of one of our near 

 neighbors to quietly settle down to ovarian statis- 

 tics. In the ovary of a pregnant potamian M. 

 Lpsueur counted twenty ripe eggs, ready to come 

 forth at the bidding of Dame Nature. Then he 

 saw a quantity of ova, varying in size from that 

 of a pin's head to the goodly volume of rotundity 

 which they attain, when the calcareous coat, which 

 is necessary for the protection of the egg when it 

 is exposed to the dangers of this world, is super- 

 added : what " the tottle of the whole" is, may 

 be ascertained by those who feel disposed to in- 

 quire of M. Lesueur ; and, if they will consult the 

 oracle, they will rise from the consultation wiser 



