552 



FROG. 



By what sort of metamorphosis it first became a frog, 

 they did not state, and in all probability they never 

 inquired. They saw the frog, and they saw the fish, 

 as they considered it to be. The fish was very con- 

 siderably larger than the frog, and that a large animal 

 should grow small was the paradox ; and as they 

 could not go this length in their simple belief, they 

 believed in something a good deal more paradoxical, 

 namely, that in this frog the process of nature is 

 reversed, and that it is frog first, and larva or tadpole 

 afterwards. Such a reversal of the order of nature 

 would have been truly marvellous, because there is 

 nothing analogous to it, throughout the whole system, 

 in any member of any class of that system which 

 undergoes transformation, and change of element and 

 breathing apparatus. Many creatures breathe through 

 the medium of water when they are in their first or 

 larva state, and afterwards, when they undergo their 

 changes, and arrive at their perfect or final form, 

 the only form under which they are capable of pro- 

 pagating their species, and which they are to retain 

 till they die, become breathers of the free atmosphere. 

 This is the case with all the frogs, and indeed with 

 all batrachian reptiles ; and the story of a frog turning 

 into a fish was about as ridiculous as that of the 

 bernacle shell turning into a wild goose, which was 

 so gravely believed, that learned men set it down in 

 print that they had actually seen the process going 

 on in some duck-pond or other in England, where a 

 bernacle, which is entirely a production of the sea, 

 could not by possibility exist. Now, the Surinam 

 frog is just as guiltless of becoming a fish, as those 

 curious mollusca, which bear their shells at the end of 

 long peduncles, which are fastened to a rock, or,in pre- 

 ference to floating wood, a ship's bottom, or anything 

 else, are of changing to geese, though the reporters 

 in both cases stand in some jeopardy of at least a 

 metaphorical transformation of this kind. 



This story, like the former, and many others 

 equally absurd, passed current in the books down to 

 about the year 1816, when Mr. W. M. Ireland studied 

 the frog through its change from the rudimental tad- 

 pole to the perfect reptile ; and Sir Everard Home 

 gave some demonstrations, aided no doubt by the 

 scalpel, the microscope, and the pencil of the highly- 

 talented and most indefatigable Francis Bauer, of the 

 internal structure of the tadpole in two different stages 

 of its growth. The actual observations by Mr. Ireland 

 might have been enough to set completely at rest a 

 question upon which rational men could have but one 

 opinion ; but still, as it is difficult to drive the nail of 

 conviction into some heads without the hammer of 

 heavy authority, it was as well that Mr. Ireland's 

 clear and satisfactory account was fortified by the 

 demonstrations of Sir Everard. The following is the 

 substance of Mr. Ireland's communication, which was 

 published in Brande's Journal for 1816 : When first 

 seen by Mr. Ireland, the tadpole was about four 

 inches and a half long by about an inch broad ; had 

 a large head and small mouth, very much resembling 

 those of a fish, though the rudiments of two legs were 

 evident just behind the head. In about a fortnight 

 the length of the animal had increased to eight inches, 

 and its breadth to about two and a half; and the rudi- 

 ments of the legs were developed into nearly perfect 

 members, with five-clawed toes, united by a mem- 

 brane, evidently the future hind legs of the animal. 



On examining its internal structure during this 

 fortnight, the intestinal canal appeared very long and 



J VJ. 



coiled up, and the rudiments of the lungs were seen in 

 the posterior part of the belly. 



Tadpole of the Surinam Frog, a quarter its length. 



In about three weeks the fore legs made their 

 appearance, the head and mouth assumed their ordi- 

 nary figure, the former being considerably smaller, 

 and the latter larger than before ; and the animal, 

 which till now had lain at the bottom of the vessel in 

 a torpid state, became more active and lively, and 

 usually remained suspended in the water, with its 

 mouth above the surface. By this time the intestinal 

 canal was wonderfully altered in extent and appearance, 

 being contracted apparently to less than half its 

 length, and having but very few short convolutions, 

 and nearly the whole of the cavity of the belly was 

 filled with fat. 



Surinam Frog, nearly full-grown, one half of real length. 



In about six weeks the animal was greatly contracted 

 in size, being little more than three inches long by 

 about an inch in breadth, and had become a perfect 

 frog, except some small remains of the tail, which had 

 been gradually sloughing off or absorbed, and the 

 disappearance of which had so greatly contracted the 

 animal's length. 



THE BULL-FROG (R. pipieni). This is a very 

 large species, by much the largest of the genus, 

 measuring not less than eighteen inches from the 

 muzzle to the extremities of the hind feet. The 

 upper part is dull green, mottled with black, and the 

 under part whitish grey, with black spots. There is 

 a copper-coloured circle on each side of the head, 

 which surrounds the tympanum, and points out the 

 place of the ear. It usually posts itself at the mouth 

 of its hole, by the side of the water. It is difficult to 

 take, being very agile, and capable of leaping to the 

 distance of ten or twelve feet at one bound. It is 

 also very voracious, feeding chiefly upon fish, though 

 it is also accused of swallowing ducklings, and even 

 goslings, in their very young state. The real bull- 

 frog does not appear to be very common, as not more 

 than a single pair usually occurs in the same pool 

 or patch of marshy ground. Cuvier is of opinion 

 that various species of frogs are confounded under 

 the general name of bull-frogs in the United States, 

 where these reptiles are of great annoyance to those 

 who reside near marshy places, which places are by 

 no means of rare occurrence in America. The com- 

 mon name of bull-frog is given from the resemblance 

 which the croaking of this species bears to the bellow- 

 ing of bulls. It is equally loud, if not louder ; and 

 as it is carried on incessantly during the night, sleep 

 is out of the question with the stranger who first 

 takes up his quarters in the neighbourhood of the 

 bull-frogs' haunts. 



