FROG 



649 



This is a very important consideration in more 

 points of view than one. In the first place it is the 

 analysis by which we must work out the theory of 

 production in all organised beings, whether plants or 

 animals, if ever we are to have any thing like rational 

 science upon this highly interesting subject. In the 

 second place it draws, more clearly than could be 

 drawn by any other means, the line of distinction be- 

 tween matter and mind, and assigns to each the limits 

 of its proper province. This is probably the more 

 important consequence of the two, because even the 

 ablest and best-intentioned of those philosophers who 

 have treated, either of the mind of man as immortal, 

 or of the material creation as demonstrating the being 

 of God, have not been able fully to disentangle them- 

 selves from the meshes of materialism. 



Frogs are exceedingly numerous ; and in their 

 productive powers they are more prolific than any 

 other vertebrated animals, with the exception of fishes. 

 Three or four hundred is a very ordinary year's pro- 

 duce from a single pair ; and the number is often as 

 many as a thousand. This extraordinary power of 

 multiplication cannot, upon the general principle of 

 the system of nature, have been given without corre- 

 sponding uses. In the case of frogs, those uses are 

 two-fold, extending both to what they eat, and what 

 eats them. We have already attended to the first of 

 these, in so far as man is concerned, and also taken 

 some slight notice of the second to the same extent. 



This is not, however, the proper view to take of the 

 system of nature, if we are to understand that system 

 aright. We are not to suppose that creation is im- 

 perfect until man puts his hand to it ; for, though it 

 has a capacity to be turned to his use to as great an 

 extent as he can possibly stretch his knowledge, yet 

 the system is in itself perfect without him ; and wild 

 nature goes on without the smallest embarrassment 

 or difficulty in those places which have never been 

 trodden by a human foot. We must, therefore, seek 

 for those uses to which the past productiveness of 

 frog applies, without any particular reference to man 

 and his operations. 



Now the number of small molluscous animals which 

 the frogs consume,and of which the productive powers 

 are also very great, and also the numbers of larvae 

 and other minute beings of the waters which they re- 

 move both in their tadpole and their mature state, 

 would be productive of unseemly mischief were it not 

 for the frogs. On the other hand, the frogs them- 

 selves supply food for a vast number of other crea- 

 tures. Birds and fishes eat the eggs while they are 

 in the waters, at that season when there is hardly 

 any other supply. The tadpoles have many enemies ; 

 and the full-grown frogs contribute largely to the sup- 

 ply of fishes, of more powerful reptiles, and of many 

 species of those birds which live on the banks of the 

 rivers. The eggs and tadpoles of frogs are also sub- 

 ject to various casualties from the seasons. They are 

 often frozen, at least the eggs are ; but whether this 

 destroys the principle of life in them, is not so clearly 

 ascertained. A frog itself can be brought to as low a 

 temperature nearly as that of freezing, without being 

 destroyed ; but in the experiments which have been 

 made, we believe that actual freezing has been in all 

 cases fatal. A more certain means of destruction is 

 drought ; for, as both humidity and atmospheric action 

 are necessary to the quickening of the eggs, they of 

 course perish if the water in which they have been 

 deposited dries up. So also if the little pools and 



runs of water into which the tadpoles distribute them- 

 selves are dried up, they, as breathers through water, 

 must perish. We need not add that, for the keep- 

 ing down of the excess of that on which they feed, 

 for the supply of those animals which feed on them, 

 and for compensating for those chances of destruction, 

 their great fertility is required. Nor must we deem it 

 strange, or at all contrary to the beauty of the system 

 of nature, or the benevolent plan of its Author, that 

 there should be a provision for those reciprocal opera- 

 tions of destroying and being destroyed ; for all the 

 tribes of beings must live upon each other ; and it is 

 this mutual support that forms the beauty of the sys- 

 tem, and which enables it, taken as an entire system, 

 to be self supported, which it could not otherwise be. 

 At a superficial glance, -we might deem this mutual 

 destruction ; but really it is the perfection of the sys- 

 tem, and without it this earth would have required 

 another earth to victual it, that would have required 

 a third, and so on without any end to the succession. 

 in other words the system of things would have 

 been absurd and impossible. Human society forms 

 no exception to this, for the more that the individuals 

 of that society depend upon one another, the more 

 abundant and the more secure are their enjoyments, 

 and the more are they disposed to cultivate all the 

 kindly charities of life. 



We need not describe the appearance of the eggs 

 or spawn of frogs, as it is familiar to every one who 

 walks in the fields in the spring months. It is, how- 

 ever, worth while shortly to advert to the transforma- 

 tion which these animals undergo. When they come 

 out of the egg, they consist of an oval head, having 

 a small mouth with a sort of horny mandibles, and au 

 elongated tail, which bears some resemblance in shape 

 to the posterior part of a fish, and has its principal 

 motions lateral, as is the case with fishes. In this 

 state they breathe by means of gills, not very unlike 

 those of fishes, as they consist of little tufts of fibres 

 fixed to the edges of small cartilaginous arches, and 

 the water passes through the fibres much in the same 

 manner as it does through those of fishes. In this 

 stage of their existence, the cavity of the body ex- 

 tends some way into the tail ; and the animal really 

 bears some sort of resemblance to a compound of a 

 reptile and fish. It was a long time before the real 

 state of the case was generally known ; and hence 

 the ridiculous stories of the spontaneous generation 

 of frogs, and of showers of them falling from the sky, 

 of which we read in the older authors. But any one 

 who chooses to observe water in which there are tad- 

 poles, and they are so abundant that there are few 

 stagnant pools without them, may see the progress of 

 the transformation. The hind feet are the first to be 

 developed ; and they are produced not from the tail, 

 which contains no part of the perfect frog, but from 

 the posterior part of the head, which head in the tad- 

 pole state is both head and body, as respects the ma- 

 ture frog. After their first appearance these hind feet 

 grow apace, and during their growth the tail hardly 

 diminishes ; but by the time that the feet can act in 

 swimming, it will be found that the tail has changed 

 both its external action and its internal structure. It 

 has become thicker laterally, its fin-like margin has 

 disappeared, and it does not act on the water with 

 that lively motion which it had in the finless tadpole. 

 Internally it has lost its muscular texture, and become 

 a reservoir of a sort of fatty substance, which by some 

 process that we do not very well understand, furnishes 



