CHAP, vi AGLOSSA 151 



are spread over the whole surface, except on the webs of the toes, 

 on the cornea and on the star-shaped points of the fingers. Each 

 papilla carries a little horny spike, and a poison-gland frequently 

 opens near its base. Larger poison-glands exist on the dorsal 

 and ventral side in four rows, and smaller glands open upon the 

 sides of the body, but there are no parotoid complexes. Slime- 

 glands occur all over the surface. The epidermis consists of the 

 usual layers, namely the Malpighian, the stratum corneum, and 

 the part which is shed periodically. The latter is completely 

 horny, appearing to be structureless like a cuticle, but it is in 

 reality composed of polygonal cells with flattened nuclei ; each 

 little spike is one modified horny cell. The whole outer- 

 most layer contains black-brown pigment. The upper portion 

 of the cutis is devoid of pigment, then follows a layer of 

 clusters of ramified dark pigment -cells, and lastly the rest of 

 the cutis. 



Each of the four fingers ends in a four-armed star, the tips of 

 which again carry four or five sensory papillae. The cartilage of 

 the terminal phalanges is correspondingly star-shaped. 



According to Klinckowstroem these toads, which are entirely 

 aquatic, are easily collected at the end of the long dry period, 

 when they are all confined to the half-dried-up pools. But 

 they do not spawn there. This happens after the rains have 

 inundated the forest, and then it is very difficult to get the 

 females with eggs on their backs. Each of the eggs, when 

 once they have been glued on to the back, sinks into an in- 

 vagination of the skin. The initial stages are probably the 

 same as those caused by the eggs on the belly of Rhacophorus 

 reticulatus (see p. 248). Later, each egg is quite concealed in a 

 cavity with a lid. These cavities are simply pouches of the .skin, 

 and are not formed by enlarged glands as has been suggested 

 by some anatomists. Each cavity consists of the epidermal 

 pouch and the lid. How the latter is produced is not known. 

 According to the authors quoted above, the lid looks like a shiny 

 or sticky layer which has hardened into horn-like consistency. 

 It lies exactly like a lid upon the rim of the pouch itself, 

 and is certainly not in structural or organic continuity with 

 the epidermis. Most probably it is produced by the remnant 

 of the egg-shell itself, which, after the larva is hatched, is 

 cast up to and remains on the top of the cup. 



