REPRODUCTION 189 



to the ditch or pond, in which they will complete their meta- 

 morphosis. The eggs are well protected and aerated by the 

 mass of air-bubbles in the frothy mass surrounding them, 

 which lasts until, after a few days, the larvae are able to move, 

 when, by the collapse of the bubbles and the liquefaction of the 

 froth, a most efficient vehicle is afforded by which the tiny larvae 

 are carried down the tunnel into the water. 



The eggs of this Rhacophorus are about one millimetre in 

 diameter and absolutely devoid of pigment ; the segmentation, 

 though holoblastic, is of a type approaching the meroblastic, as 

 in other Batrachian eggs containing much yolk ; the embryo 

 is at first quite distinct from the yolk. Eggs taken from the 

 nest invariably die if put into water. The tadpoles, when leav- 

 ing the nest, are said to resemble those of ordinary frogs. 



Some species of the South American Cystignathid genera 

 Leptodactylus and Paludicola have been observed to treat their 

 eggs in a somewhat similar manner. In the breeding season 

 the parents prepare a hole under a stone or decayed wood, near 

 the edge of a pool, above the water-line. The eggs, in small 

 number and of light colour, are also surrounded by a frothy 

 substance, in which the larvae attain a certain development, until, 

 after rain, the pool overflows and they are washed into it. 



The little Australian Bufonid, Pseudophryne, deposits its 

 large eggs under stones or on the edge of a dried-up pool. The 

 larvae do not emerge until rain has again filled the pool. 



(1) C. Some tree-frogs, Phyllomedusa in South America, 

 Rhacophorus malabaricas in India, and Chiromantis in tropical 

 Africa, deposit their spawn on trees, in nests of froth attached 

 to a leaf or to several leaves stuck together, and overhanging a 

 pool. The larvae move with considerable freedom in the frothy 

 mass, and after a few days, having lost the external gills, drop 

 into the water, where they complete their metamorphosis in the 

 ordinary way. As in the preceding forms, the eggs contain 

 much yolk, and are comparatively few in number, viz. not 

 over 200. 



Nests very similar to the above have been observed in 

 Japan, and ascribed to Rhacophorus schlegelii, but this deter- 

 mination requires confirmation. Other species of Rhacophorus 

 inhabiting India and Ceylon, produce masses of green frothy 

 spawn which have been found sticking to the walls of wells, per- 



