REPTILES. 271 



The naturalist, however, finds that the power of the Almighty 

 is manifested with as much glory in these vile objects of universal 

 detestation as in the more favoured races of creation. He sees 

 nothing in the class of Reptiles but animals singular in their forms, 

 curious in their structure, marvellous in their metamorphoses, and 

 admirably adapted by their habits to the duties imposed upon 

 their different races. Few beings, indeed, are more worthy of the 

 attention of the thinking observer than these proscribed and per- 

 secuted creatures ; and, as the reader need not fear to accompany 

 us into their gloomy haunts, we may at least peep behind the 

 broken masses of rock where they hide, display them coiled up 

 beneath the rotting vegetation of the forest, see them swimming 

 in the streams or wallowing in the marshes, and observe the 

 mechanism by which they have been enabled to creep, or climb, 

 or walk, or run, or leap, or even fly. Neither are they ill adapted 

 for their appointed localities, or inharmonious with the scene 

 around them. It is in the dismal swamps of tropical regions that 

 we must see the Reptile races in their full luxuriance where the 

 rivers slowly roll along their sluggish waves, or spread out in 

 broad swamps, which far and wide cover the alluvial slime they 

 have deposited. These vast morasses, steaming with foetid fogs 

 and pestiferous exhalations, alternately inundated and left dry, 

 where earth and water appear to contend for undefined posses- 

 sion, are peopled only by the Reptile forms indigenous to such 

 localities. Enormous serpents, trailing their length along, impress 

 the miry soil with tortuous tracks. Crocodiles and toads -knead 

 with their sprawling feet the yielding clay ; huge alligators lurk 

 in ambush, and a thousand hideous things withdraw themselves 

 from observation. The reptile occupying this intermediate do- 

 main, between the waters and the land, is neither a perfect quad- 

 ruped nor a true fish, but a sort of ambiguous production sharing 

 the attributes of both. Let us, however, examine their structure 

 a little more closely. 



In Reptiles the circulation is arranged in such a manner that 

 the heart, at each contraction, sends into the lungs only a small 

 portion of the blood received from the various parts of the body ; 

 so that the bulk of the circulating fluid returns to the system 

 without having passed through the lungs and undergone the 

 process of respiration. 



It is respiration that communicates to the blood its heat and 

 to the muscles their irritability. We find, therefore, that Reptiles 

 have cold blood, and that their muscular power is, upon the whole, 



