

We LIVERPOOL BIOLOGICAL SOCIETY. 
analogous to the aqueous’ humour of the paired eye, whilst, 
as pointed out above, we can compare the fluid of the. 
vesicle with the vitreous humour. 
PINEAL EYE OF THE EMBRYONIC PELIAS BERUS. 
In the last of his ‘‘conclusions’” Spencer says, that 
the pineal eye ‘‘is found amongst lving forms only in 
Lacertilia,’’ and, as far as I know, no author has described 
a pineal eye in the Ophidia. On examining an embryonic 
adder, Pelias berus, in the Zoological Museum of the 
College, and brought by Professor Herdman from the 
island of Arran, I found an organ which I have no doubt 
is the pineal eye. The lens is remarkable for its conical 
form, the broad base of the cone being directed dorsally, 
and for the large mass of pigment which lies in its centre. 
This arrangement of the pigment in the centre of the lens 
of the pineal eye, is not quite unknown. The same has 
been found by Spencer in Varanus, one of the Lacertilia. 
I was not able to make out other histological details about 
the pineal eye of the adder, as the specimen examined was 
not in a satisfactory condition, having been for a long time 
in rather weak spirit. 
Perhaps I may now be permitted to make some specula- 
tions on the pineal eye of Angwis fragilis. That organ is 
generally said to be rudimentary, and to have been an 
organ of sight in former periods. I cannot agree with 
these views, and in my arguments against the same, I 
start from the fact, that the pineal eye is far more highly 
developed in the adult than in the young Angwis ; and 
therefore it cannot be a rudimentary organ. We must 
suppose, then, that the pineal eye is still in function, and I 
have no doubt that it is in some way of use as a seeing 
organ. But certainly the function of seeing is here only 

