210 THE DEVELOPMENT OF THE TADPOLE. 



information as to the nature or name of the structure described, 

 they would confer a great favour upon him. And here, if a 

 suggestion may be permitted, he would ask why the pages of this 

 Magazine should not be made a true vehicle of communication 

 between the members of the Postal Microscopical Society and 

 the readers generally. After this confession of error, which was 

 due to my readers, an attempt shall be made to give an account 

 of my observations on the growth of the limbs of the frog. 



All who have ever watched frog-tadpoles, even slightly, must 

 have observed that the hind-legs are apparently produced before 

 the front-limbs. Animals, with beautifully long tails which they 

 use with the utmost freedom and grace in propeUing themselves 

 through the water, are seen also to possess two small but complete 

 hind-limbs, which are apparently perfect long before there is any 

 visible trace of the fore-legs. Thus, with respect to a set of 

 animals which were carefully watched, the hind-legs were well out 

 on June 4th, but the fore-limbs were not seen till eight days later, 

 or on June 12th, and by the 22nd of the month the tail had nearly 

 disappeared. 



Now comes a most critical period in the life of these little 

 creatures. When just in this stage of what may be termed half 

 fish and half frog, should the conditions of existence be the least 

 unfavourable, they die off most rapidly, so that out of a large 

 colony not one will remain. Deep water, with no resting place 

 on the top, is absolutely fatal. The creature now requires 

 atmospheric air at short intervals, and should be placed either in 

 a shallow vessel or in a tank where it can rest on substances 

 placed just under the surface of the water, so as to keep its body 

 moist, whilst its nostrils may be readily raised out of the water, 

 and even under these circumstances they will all disappear in a 

 few days, hopping off to damp grass, there to hide during the 

 day in any shady nook, and at night swarming forth in such num- 

 bers, especially after a slight shower, as to make many people 

 believe in showers of frogs. 



As then the hind-legs are the first to shew themselves, our 

 observations shall first apply to them, but in truth the front-legs 

 are growing at the same time, the only difference being that these 

 are hidden from sight, whilst those are to be seen almost from the 



