RANDOM NOTES ON NATURAL HISTORY. 



heat production. No one, but all organs 

 have to do with heat production, which is 

 directly brought about by motion and oxi- 

 dation ; a slow combustion disposing of or- 

 ganic waste. In the " warm-blooded " ani- 

 mals the circulatory system is so constructed 

 as to keep the venous, charged with carbon 

 and other impurities, separate from the 

 pure arterial blood. This impure blood is 

 not only purified in the lungs, but carries 

 with it, to the different tissues, no small 

 amount of oxA'gen. Considerable heat, 

 brought about by the chemical union of 

 oxygen and carbon, is thus produced not 

 onl^' in the lungs but throughout the bod}'. 

 In the "cold-blooded" vertebrates the 

 heart mixes arterial and venous blood, 

 thus sending to the lungs or gills, or both 

 lungs and gills, as the case may be, blood 

 that is only partially charged with impure 

 matter ; the resulting oxidation must hence 

 be slow and the heat produced of a low de- 

 gree. The amount of heat is further re- 

 duced in those forms breathing by means of 

 gills, b}' the comparatively small amount of 

 oxygen in the water. It must not be 

 thought, however, that the lungs alone are 

 the heat producers ; the several organs of 

 the body assist, as well as all physical move- 

 ment, the sum total resulting in a '- warm" 

 or "cold-blooded" animal, as the case ma}'^ 

 be. 



Reptiles, which are represented in Rhode 

 Island by turtles, lizards, and snakes, diff"er 

 from the Batrachians, toads, frogs, sala- 

 manders, and newts, in several particulars. 

 While reptiles are hatched or born in form 

 and structure differing from the adult only 

 in respect to size, the immature Batrachians 

 are strikingly unlike the adult ; in their 

 mode of breathing and progression much 

 more resembling fishes, from which they 

 reach the mature form through a succession 

 of metamorphoses. A second, and possi- 

 bly a more obvious distinction, is in the 

 dermal covering ; all our Reptiles being pro- 

 tected by scale-like folds of skin, while the 

 Batrachians are without this means of pro- 

 tection, having the skin moist and pliable. 



In members of both classes intelligence 

 is of an extremely low order, one or more 

 of the special sense organs is often atro- 

 phied. Growth is slow and often continuous 

 through life, which is often greatly pro- 

 tracted. From an economic standpoint 

 both Reptiles and Batrachians form import- 



ant checks against the undue increase of 

 destructive vermin, and the flesli of turtles, 

 some lizards, and many Batrachians is an 

 important addition to tiic table. Confining 

 our attention to such Reptiles as may be 

 found in our locality, we find representatives 

 of three orders: Testudinata, Sauria, and 

 Ophidia. 



The first order includes the turtles and 

 tortoises; animals with keen sight, rather 

 acute hearing, but with smell and taste 

 somewhat dull. All turtles are oviparous, 

 depositing the eggs, which are fertilized in 

 the oviducts, in sand to be hatched by 

 solar heat. The males are externally distin- 

 guished from the females by having a con- 

 cave j)/asfro» (the lower portion of the shell) , 

 and some of the sea-turtles are provided with 

 stout hooks on the fore flippers. 



The second order, Sauria, including the 

 lizards, is with difficulty separated, because 

 of some of its representatives, from the 

 third. The only form likely to be captured 

 in Rhode Island, however, shows few ophi- 

 dian tendencies. 



The third, and last order of Rhode Island 

 Reptiles, includes the snakes, under the 

 term Ophidia. The snakes have keen sight ; 

 except just previous to the time of moult- 

 ing, when the cleaving epiderra, which 

 covers the eyes, renders them partially 

 blind. The sense of smell is probably well 

 developed, judging from the strong odor 

 given off by many species during the breed- 

 ing season. Hearing is dull, and no exter- 

 nal ears are to be seen. Taste is probably 

 wanting, the tongue being used as a tactile 

 organ. Though some foreign snakes incu- 

 bate their eggs, our species, if oviparous, 

 leave them to care for themselves much as 

 do the turtles. Some of our forms, how- 

 ever, are viviparous. 



The facts do not warrant the popular be- 

 lief that the young, in time of danger, seek 

 safety by allowing the parent to swallow 

 them. Nor is it true that the snake covers 

 its prey with slime previous to deglutition. 

 Intelligent people need not be cautioned 

 against crediting the oft-heard stories of 

 " charming," and of " hoop-snakes." The 

 ready, but fallacious, method of determin- 

 ing the Rattler's age by adding three to the 

 number of rattles, has became so securely 

 the property of newspaper reporters as to 

 banish all hope for more truthful things. 



