212 SCIENCE FROM AN EASY CHAIR 



out and becomes, relatively to the increased size of the 

 body, quite short. 



Even those who know frog-spawn when they see it 

 and something of the history of the growth of the tad- 

 pole and its change into the young frog or toad (as the 

 case may be) do not, as a rule, know about the laying of the 

 eggs. In the early spring (end of March) the full-grown 

 frogs and toads which have passed the winter buried in 

 holes and cracks in the ground in a state of torpor wake 

 up and make their way to neighbouring good-sized 

 ponds. In these the eggs are deposited. The male 

 frogs wait for the females whom they seize from behind, 

 placing their arms under hers and round the chest. 

 They hold so firmly that nothing will persuade them to 

 let go. They often retain their hold for days or even 

 weeks. Sometimes by mistake they seize a fish and 

 hold on securely to its head a fact which has led to the 

 belief among country-folk that the frog is an enemy 

 of the carp, and tries to blind him by forcing his 

 hands into the carp's eyes. At this season a frog will 

 clasp your finger or the handle of a stick so persistently 

 that you can lift him out of the water. A large pad of a 

 black colour grows in the breeding-season on the inside 

 of the first finger of the frog's hand, and is richly 

 supplied with nerves. It is this growth which is sensi- 

 tive and when touched sets up the cramp-like clasping 

 action of the muscles of the arms. The eggs are 

 eventually squeezed from the female's body, and are 

 fertilised by the spermatic fluid of the male as they 

 pass into the water. They are, when " laid," covered 

 with only a thin transparent layer of albumen (or white 

 of egg), and it is only after a few hours that this imbibes 

 water and swells up into a ball-like mass around each 

 little black egg. 



Years ago I used to collect the spawning toads and 



