THE NATTERJACK. 137 



Mr. Hepworth, of Wakefield, has made some 

 curious calculations and investigations on the pro- 

 lific nature of frogs and toads, as well as contributed 

 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. Hepworth 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 diame- 

 ter 9,650, or rather more than half the number 

 obtained from Mr. Couch's measurement in the case 

 of the natterjack." This, he argues, is nearly the 

 same in effect, " when we consider that there are 

 two rows in the spawn of the natterjack, while in 

 the common toad there is only one." As the calcu- 

 lation is based upon the space occupied by a single 



* The Naturalist, vol. i., pp. 24, 73, &c. Hudderafield, 18G5. 



