26 



fauce?:, oarh 63°: tho water in wliich thcv lav, and wliich was now 

 remowd, gave 58^°; other water GO''. 



A\m\ 3(1, 7, A. M. — the anhnals and tlieir cages are quite dry ; air 

 64°; groins, gullet, etc., each 63°. Noon, air 68*; alligators 65. 

 Sunset, air 64°; alligators nearly 65, and dry. 



April 4lh, 1, p.m. — air 63°; flanks 60^; gullet 61*. Sundown, air, 

 flanks and gullet, each 64°; animals dry. 



The following experiments are deemed relevant to this subject : — 

 While engaged in making a most extensive series of thermometrical 

 observations, illustrative of the diurnal and annual temperature of the 

 Mississippi River, I have had a few opportunities of experimenting on 

 its fishes, immediately after they were taken out of the water — an 

 example of which is here subjoined. 1845, July 29, air at 5^, at 6, 

 and at 6^, a. m., 76°; River 85-^°; a fish {percaf") weighing about three 

 pounds, was (after crushing its brain) placed on a plank, in a shade, with 

 a thermometer thrust into the gullet. In two minutes, the temperature 

 was 81°, in 3 m. 81°, in 5 m. 80f°, (dead) 5 m. 80°, (body flexible) 

 10 m. 80°, 10 m. 79f°, 20 m- 79|°, (now one hour — body somewhat 

 rigid) 10 m. 79^° (universal rigidity) 10 m. 79^°. During these ex- 

 periments, the air of the spot had raised to 83°; and had now, in one 

 and a half hours, begun to communicate its caloric to the fish. 



It may, perhaps, be said, that the crocodile of modern times differs 

 from that of the ancient world. Fortunately there is a history extant, 

 written with a pen altogether infallible ; it reaches to the earliest era of 

 our planet — The fossiliferous volume of mature. The author of 

 the Recherches sur Jes Ossemens Fosslles, formed a new era. He had 

 surveyed the face of the old, scarred earth, and numbered its animals. 

 He penetrated below its surface — he disinterred the fossilized past. 

 Thus Cuvier, like Columbus, discovered a new world ! What the 

 inimitable Bulwer says of the mysterious /z/^z/r^^, may, with little modifi- 

 cation, apply to the past — anterior to Cuvier's great revelation concern- 

 ing the fossil remains of eras so remote, as to bewilder the imagination : 

 " upon that unknown and voiceless gulf of inquiry, brooded an eternal 

 and impenetrable gloom — no wind breathed over it — no wave agitated 

 its stillness -, — over the dead and solid calm there was no change pro- 

 pitious to adventure — there v.ent forth no vessel of research, which was 

 not driven, baffled, and broken again upon the shore." 



Thanks to Cuvier ! Zoologists can now say with Dr. Buckland, in his 

 Bridgewatcr Treatise, "that the fossil remains of the crocodilian family 

 do not deviate sufficientlvfrom living genera, to require any description.'' 

 -~(V. i., p. 101.) 



Microscopic Addendum. 



The epidermis, cuticle, or scarf skin of the alligator, consists of a 

 laminated horny substance, which, nevertheless, transmits the sense of 

 touch with rapidity. A live coal placed on the skin, directly over the 

 .'^pwie, caused an instantaneous manifestation of pain, which seemed to 

 be acute. 



=^ Fiiinily Pcrndic, frmus Pomo/is. Mr. De Kav. New York Faima. 4to. 



