26 The Third and Fourth Generation 



When the eggs are laid each is inclosed in a 

 capsule of jelly, so sticky that adjacent eggs 

 adhere in masses or, in the case of the toad, in 

 strings. The masses are as large as the clenched 

 fist of a child and are found attached to grass 

 stems, rushes, or twigs in the shallow parts of 

 the ponds. Frogs seem to have regular egg- 

 laying bees, so that one often finds a peck or 

 more of egg masses at one favorite spot. Some- 

 times the sedgy margin of a stream will be 

 festooned for rods with floating strings of toads' 

 eggs. But you must be out collecting early in 

 the morning if you would catch the eggs by the 

 time the first division is accomplished. This 

 first plane of cleavage runs from the dark pole 

 to the light, and each little black bead separates 

 into two that lie in close contact, two adherent 

 cells in place of the one (Plate II) . In the cold 

 ice water of the pond development goes on 

 rather slowly, but if the eggs are brought into 

 the house in some of the pond water they 

 proceed to cleave rapidly as they become 

 warmer. Two cells become four in an hour 

 or less, four change to eight in still less time, 



