94 Trans. Acad. Sci. of St. Louis. 
there does not even seem to be any muscular tissue in 
the upper lid which might serve as a levator. Yet, the 
eyelids are evidently transparent enough to transmit a 
considerable amount of light. Mr. Hurter tells me that 
he found at least one specimen of T'yphlotriton crawling 
on a rock outside of and quite a distance removed from 
the entrance of Marble Cave. This seems to show that 
the animal is not blind in the full sense of the word, or 
at least that some individuals do not always live in the 
darkness of the cave. 3 
Kigenmann says: ‘‘The six normal eye muscles were 
present in Typhlotriton. The musculi recti form a sheath 
about the optic nerve in its distal part and spread out 
from it near the eye.’’ It is hard to understand what 
is meant by this description. There is, as far as I can 
see, much muscular tissue in the neighborhood of the 
eye, but it has not been my good fortune to see one, much 
less the six normal muscles insert themselves into the 
sclerotic. In fact the only muscular tissue which seems 
to merge into the sclerotic reaches backward from: the 
posterior pole of the eye enveloping the optic nerve. It 
seems ‘to form a rather thick and broad band which is 
attached to the sphenoid bone. It would seem that this 
muscle might act as a retractor oculi. (See Figs. 9 
and 10.) 
EXPLANATION OF THE PLATES. 
Plate XXVI.—Fig. 1. Vertical section through the eye of the larva 
of Typhlotriton which still had gills. No evidence of lid formation. 
Cornea covered with epithelium which is flattened and differs mate- 
rially from that on the surrounding skin. The retina does not lie in 
the normal position since the eye is shrunken, but shows the different 
layers well. A separation between the two outermost layers of cells 
and the remainder of the retina is quite noticeable. Fig. 2. Vertical 
section through the eye of a Typhlotriton, probably just about reaching 
the adult state. This specimen showed no gills, yet, no eyelids have 
as yet been formed. Perhaps, the protruding fold seen on the left 
side of the cornea is the beginning of the lower eyelid. In this figure, 
too, although not as well as in figure 1, a separation of the two outer- 
most layers of the cells of the retina from the broad nuclear layer 
is visible.’ 
