BREEDING HABIT AND DEVELOP. OF RACOPHORUS. 



117 



and that this species deposits its eggs under ground as well as on trees, 

 shrubs, and grasses. 



Egg -mass. 



The eggs, when laid as stated ahove, are enveloped in a white 

 jelly-mass full of air-bubbles, and of a spheroidal form. The surface of 

 the mass is generally dirty from mud and earth particles adhering to 

 it, while the interior remains pure white. The bubbles in the jelly 

 mass vary in size, but are commonly 2 — 8 mm. in diameter, and are 

 spherical in form. The snow-like appearance of this mass is entirely due 

 to the presence of bubbles, as the fact that certain portions free from 

 them remain transparent well proves, so that the comparison of such 

 a mass to froth formed of well-beaten white of hen's egg is more than 

 superficial. The newly laid mass is very elastic and tenacious, but with 

 the lapse of time, it becomes gradually less elastic and less tenacious, so 

 as to run down. The mass is then no longer able to keep its shape and 

 flattens down gradually with the loss of air-bubbles in it, until finally it 

 becomes so liquid as to flow out of the hollow into the water. By 

 this time, the eggs have hatched into tadpoles, which are of course 

 adapted to life in water. The outlet, through which the melted mass 

 of the jelly runs down into the water, is the orifice previously made by 

 the parents when they went out of the hollow through the thin portion 

 of its wall above mentioned. This circumstance beautifully explains 

 the reason why the egg-nests are never placed far from water. Both 

 too much wetness and dryness seem equally injurious to the development 

 of eggs. Those that have not yet hatched can never thrive in water, 

 and if placed artificially in it by way of experiment, they soon die. On 

 the contrary, I once saw some years ago, at Echigo, a nest of the 

 species hanging down about 2 feet above water between the leaves of J ug- 

 hins Sieboldiana (.Jap — Onigurumi) near the bank of a ditch ; it was 

 entirely dried up like a piece of dry bread, with many dead eggs in it. 



What purpose does this frothy envelope of eggs serve ? I ani: 

 inclined to answer the question as follows : — 



