REPORT OF THE DIRECTOR I918 263 



alternating spots of light and dark gray; the light spot of one side 

 opposite the dark of the other. 



June 12th. Length, 13.8 mm (plate 7, figure 5). 



Larvae free from gelatinous envelops of eggs. No marked changes 

 except in development of fingers and a slight increase in size. Color 

 pattern slightly modified by coalescence of spots on the back of 

 trunk and tail. The figure is of interest particularly because it 

 shows the extremely compressed, wedge-shaped body. 



June 19th. Length 15 mm (plate 7, figure 6). 



Gills about half their original length ; arms and hands fully devel- 

 oped, the second and third fingers proportionally longer than in 

 the adult. Legs with middle joint free, feet with three toes. Body 

 and tail robust and taking on adult proportions. Center line of 

 back with a series of light gray spots diminishing from before back- 

 ward and bordered by darker gray, the result of fusion of the 

 alternating spots developed in a previous stage. 



June 20th. The single specimen showing reduction of gills, 

 found dead on this date. Attempts to secure additional specimens 

 to complete the series of development stages and show final reduction 

 of the gills were unsuccessful. The sphagnum of the bogs bordering 

 Featherstone lake (near Mariahville, N. Y.) was examined and 

 search made in the thick moss growing about the bases of stumps 

 on the edge of a small hill-top pond, near Ballston lake. New York, 

 but without results. 



The amount of yolk in the eggs of Hemidactylium is proportionally 

 smaller than that found in P. cinereus or D. fuscus. In 

 other words, the developing embryos of Hemidactylium have greater 

 bulk compared to the mass of the yolk than is the case in the other 

 species mentioned. In that stage of development of D. fuscus 

 in which arm and gill buds are evident from surface views, the 

 embryo is of relatively small size and encircles the egg (Hilton '09, 

 plate 4, figures 47-48). Practically the same is true of P . cine- 

 reus. In Hemidactylium, however, by the time the gill and 

 arm buds are well formed, the yolk mass is confined to the abdominal 

 region of the embryo and greatly diminished; even at an earlier 

 stage considerable reduction of yolk is evident (plate 6, figures 5-6; 

 plate 7, figure i). The condition of Hemidactylium is perhaps 

 nearer that found in Eurycea (Spelerpes) bislineata 

 whose eggs are deposited in water (Wilder '99). 



Early absorption of the yolk presupposes ability in the young 

 larvae to take food independently soon after leaving the egg; but 

 specimens observed, although capable of considerable movement, 



