288 FROGS AND TOADS. 



thickened and the eggs, as soon as laid, are taken by the males and embedded one 

 by one in this softened skin, which soon closes over, so as to enclose each in a 

 separate cell. In these cells the eggs undergo the full course of development, the 

 juvenile toads issuing forth from their confinement in a perfect condition, although 

 their dimensions are, of course, small, and no gills being developed at any stage. 

 Although there may be as many as one hundred and twenty cells in the back of a 



C%z 



FEMALE SURINAM WATER-TOAD, SHOWING YOUNG IN* THEIR CELLS (^ liat. Size 



single individual, the more usual number is from sixty to seventy. The period 

 from the deposition of the eggs to the appearance of the young toads is eighty-two 

 days, and the young, when first bursting through the covering of their cells, 

 generally protrude the head or one limb. Soon after the birth of her offspring the 

 female changes the superficial layer of her skin by rubbing it off against stones or 

 plants ; the place occupied by each cell being then indicated by a small pit. 

 Except during the breeding-season, the pipa appears to be completely aquatic. 



