164 DKPOSITION OF SPAWN. 



they undergo in the early period of their history. The trans- 

 formation of a Tadpole into a Frog exhibits, in the successive 

 phases of the life of an individual animal, substantially the same 

 stages of advancement towards a higher type of organization as 

 are marked by the mature forms of the several members of the 

 group as a whole. It will be interesting therefore to notice by 

 what steps this progressive improvement of structure is made ; 

 and as there is no lack of Tadpoles in our ponds and ditches 

 throughout the spring and fearly part of summer, any of our 

 readers who choose to do so may readily verify our statements for 

 themselves. 



In the beginning of March, then, the Frogs which all the 

 winter through have been comfortably " conglobulated " together, 

 as Dr. Johnson said of the swallows, in the mud at the bottom 

 of the ponds and ditches, wake up from their protracted sleep, 

 and make their appearance at the surface of the water. In a 

 little while they are all busily engaged in their nuptial rites, with 

 respect to which the only remark we have to make is, that we 

 wish they were somewhat less obtrusively thrust upon our notice. 

 The eggs are deposited in large masses at the bottom of the 

 water ; but as each egg is surrounded by a covering of glutinous 

 matter, which readily absorbs water, the entire mass speedily 

 swells, and becoming lighter than the surrounding medium, it 

 rises to the surface. In this stage the eggs appear as little black 

 dots, separated from each other by a globular investment of 

 transparent colourless jelly ; and it is only by bearing in mind the 

 extraordinary abundance in which this spawn is to be seen in 

 the water in spring, that one can account for the myriads of tiny 

 Frogs to be found hopping about the margins of the ponds later 

 in the year. For about a month or five weeks the eggs gradually 

 increase in size ; at the end of that period the young Frogs as 

 yet, however, far otherwise than Frogs in form burst the en- 

 velopes of the eggs, eat their way through the gelatinous walls 

 that imprison them, and make their escape into the water. 



In the condition in which the little creature commences its 

 active life, it is known to every village urchin in the land as the 

 Tadpole, or Loggerhead. The Cockney schoolboys give it the 

 more expressive name of Tiddler. The little thing seems all 

 head and tail. " It is provided," says Cuvier, " with a long fleshy 

 tail and a small horny beak, and has no other apparent members 



