74 POPULAR SCIENCE MONTHLY. 



ricans. Having taken the eggs, however this may be done, the frog 

 emits a clear musical sound and goes hunting its own food, thinking, 

 we may suppose, as little of its offspring as do our own common toads 

 and frogs. The young require a long time to bring them to the 

 hatching stage, and have also an unusually large and peculiar gill on 

 each side. 



The tree-frogs of the tropics furnish examples of egg-carrying 

 habit as well as of nest-building. Thus in Ceylon a tree-frog (Rhacoph- 

 orus reticulatus) carries its eggs in a cake-shaped cluster of about 

 twenty firmly fixed to its belly, as indicated in Fig. 6. This time 

 it is not the male, but the female, that aids the coming race by giving 

 it transportation and protection. Probably, however, it is the male and 

 not the female of a frog of the Seychell Islands ( Anthroleptes Seychel- 

 lensis) that carries about its young on its back. This is a most complex 

 case, for the eggs are laid upon moist earth or rotten logs and kept 

 moist by the body of the frog until they hatch; they have large tails. 



Fig. 7. Fig. 8. 



and even the beginning of hind legs. Then the youngsters get up on 

 the back of their parent and stick there till their development is com- 

 plete. The peculiar little tadpoles have great power of adhesion, and 

 can stick to the sides of a glass dish as they do to their parent's back 

 (Fig. 7). Another such case occurs in Trinidad and in Venezuela. 

 When the ponds dry up the young tadpoles of the frog Phyllohates 

 trinitates, which are as yet without legs, though they have tails, stick 

 themselves firmly to the back of the male frog (whether it is their 

 father or the father of some other tadpoles does not appear), and in 

 this way are carried 'pick-a-back' to some larger pond. Similar habits 

 have been observed in the frogs Dendrohates Irivittatus and Dendro- 

 hates hraccatus. 



Again, a frog (Hylodes liniatus) of Dutch Guiana is found with 

 its tadpoles attached to its back, as seen in Fig. 8. The young, 

 from a dozen to twenty, are attached, as shown, with their heads 

 turned towards the middle of the mother's back and do not fall off, 

 even when she leaps rapidly away. Thus the mother, and not the 



