172 DISCOGLOSSlDtf!. 



follows that whereas some may have spent only three 

 or four months in the water, their brothers will 

 sojourn for a whole year or more in that element. 

 Young reared by me measured, immediately after meta- 

 morphosis, from 18 to 22 mm. from snout to vent. 



Eggs. — Large, the vitellus measuring 3J to 5 mm. in 



diameter, varying in colour from pale straw-yellow to 



bright yellow. They are coated with 



Fig. 63. two transparent gelatinous envelops, 



the outer of which is tough and elastic, 



and forms the threads by which the eggs 



are connected in two rosary-like series 



as they issue from the cloaca. These 



connecting threads measure, without 



great tension, from 4 to 7 mm., and 



according to the number of eggs, which 



varies between 18 and 54, the whole 



rosary has a length of 70 cm. to 2 m. Males observed 



by Geisenheyner and Melsheimer with 126 and 150 



eggs were no doubt nursing double or treble broods. 



When fresh laid the eggs are nearly spherical, 

 but they soon acquire a more transversely oval 

 shape. Through the transparent capsules the 

 whole development can be easily followed. An 

 enormously large vitelline sac is present, and the em- 

 bryo develops uncommonly long, unpigmented gills, 

 one only on each side, with a large number of slender 

 branches along the ventral side of the trunk. These 

 gills are absorbed and replaced by internal ones, and 

 the transformations which accompany the passage from 

 the first or embryonic to the second or tadpole period 

 are all effected within the egg-capsules. The embryos 

 are at first uniform yellowish-white ; the pigment, 

 when it appears, forms two brown stripes, but before 

 hatching the little tadpole has put on his grey, 

 more or less spotted coloration. 



Tadpole (PI. I, figs. 4 and 5). — Length of body once 

 and one-third to once and a half its width, two-fifths 

 to one-half the length of the tail. Nostrils nearly 



