376 Charles R. Stockard. 
are collected into optic nerves which pursue extraordinary courses; 
instead of passing through the outer retinal layers and the choroid 
coat they take an almost directly opposite course and run across 
what should be the optic cup cavity (the humor cavity in these 
specimens is filled with loose cellular tissue) and out through the 
wide-open ‘‘pupil,”’ forming a perfect cross and then passing into 
the base of the brain to end in the optic lobes. 
The position of the lens must not be supposed to determine the 
actual pupil region of these eyes, as the lens clearly lies between 
them; see fig. 4 of the living embryo. The wide open pupils of 
the two eyes face or lead directly into one another. The position 
might be taken that the entire arrangement represents one 
large eye; this is not true however since the eyes are entirely 
separate in all of the sections and the optic cross could searcely be 
expected to exist within the base of the eye itself as would be the 
case if this were one huge eye. The eyes really hang down from 
the brain as two large retinal disks. Fig. 11 represents a similar 
case with the eyes rather more flattened out laterally, and the 
existence of all gradations between the two conditions substan- 
tiates the above statement. 
The retinal layers of these eyes which are nineteen days old, 
are poorly differentiated, the inner layer consisting. merely of 
indefinitely arranged cells; a better differentiation is usually 
attained in normal specimens by the sixth or seventh day. A 
comparison of Figs. 13 and 14 with Fig. 12 illustrates in a way the 
more definite orientation of the inner retinal cells in the normal 
individual when compared with the defective eyes. It will also 
be noticed that the lenses in. the two-eyed specimen are surrounded 
by clear humor spaces while the lens in the defective eyes lies 
buried in loosely arranged cellular tissue. 
The right retina of the monster faces in the same direction as 
the left retina of the ordinary individual yet there is no indication 
of a reversal of the layers which might possibly beimagined in such 
a case. 
The optic stalk was scarcely formed in these eyes, which is 
not infrequently true in cyclopia. The path of the optic 
nerve is, therefore, evidently not that usually taken along the 
