FIG. 90. LIFE-HISTORY OF THE FROG. 



Some clusters of eggs are seen, each egg surrounded by a sphere of 

 jelly, which is in several ways protective, e.g. in saving the developing 

 eggs from being crowded and jostled. It is also unpalatable to most 

 water-animals. Each ovum is about a tenth of an inch in diameter ; the 

 jelly swells up into a much larger sphere. One of the eggs is shown on 

 a larger scale, with the tadpole ready to emerge. 



Hanging on to the water-weed, by means of a glandular adhesive organ, 

 are the newly hatched tadpoles still mouthless, gill-less, and blind. 



The tadpole above the figure 2 is about tw r o months old ; it is breathing 

 by its second set of gills ; the hind-legs have budded out. 



The tadpole opposite 3 is nearly three months old. The tail is being 

 absorbed, the lungs have developed, a metamorphosis is being accom- 

 plished, after which it leaves the water as a tiny frog (4). 



279 



