138 OUR REPTILES. 



proximation to Shaw's description. There is, 

 however, a very appreciable odour under certain 

 conditions of excitement, &c. 



Mr. Hepworth, of Wakefield, has made some 

 curious calculations and investigations on the 

 prolific nature of frogs and toads, as well as con- 

 tributed useful observations on their enemies 

 whilst in the larval state.* Mr. Couch having 

 recorded that on one occasion he had drawn out 

 and measured one of the strings of ova deposited 

 by the natterjack, and had found it at least one 

 hundred feet in length, Mr. Hep worth calculates 

 that as these strings are double, and allowing 

 eight ova to the linear inch, the number of eggs 

 deposited by one female toad of this species 

 would reach not less than nineteen thousand. He 

 afterwards makes an independent calculation on 

 the common toad. " I have taken four inches as 

 the average diameter of these masses (of ova). 

 Now, as there are eight eggs in one linear inch, 

 and six strings laid side by side fill the same 

 space, we shall have for one cubic inch 288 

 germs, and in a globular mass of four inches 

 diameter 9,650, or rather more than half the 

 number obtained from Mr. Couch's measurement 

 in the case of the natterjack." This, he argues, 



* The Naturalist, vol. i. pp. 24, 73, &c. Huddersfield, 

 1865. 



