sought the darkest part of the space in which they were 
nfined 
The second distinct phase in the metamorphosis, which, how- 
ever, commenced in every instance before the change in color 
had made much progress, was the absorption of the dorsal and 
caudal membranes, This began on the lower margin of the 
tail, and soon after could be detected in the dorsal region, and 
then farther back, the last portion remaining being usually on 
oot il part of the tail. The absorption extended below the 
dorsal surface, leaving at first a groove along the back, marki 
the position of the membrane; and as this disappeared the light 
colored specimens retained in its place a narrow black line, 
which extended also to the end of the tail. 
ee P * 
Marked alteration in the shape of the head, which occurred 
about the same time. In the todo state the head is broad- 
‘st at the base, and comparatively flat above (figures 1 and 1 a), 
but after the loss of the branchial arches, its test breadth 
Was a little back of the eyes, while it was much more rounded 
