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Zoology. — “On an eel, having its left eye in the lower jaw’. By 
Mrs. C. E. DROOGLERVER Fortuyn—van LEYDEN. (Communi- 
cated by Prof. J. BOEKE). 
(Communicated in the meeting of Februry 24, 1917). 
Through the kindness of Dr. H. C. Repere I obtained an eel in 
which the left eye was lacking in the ordinary place, while on the 
lower side of the head, somewhat to the left of the medial line, an 
eye was visible which externally was quite normally shaped. 
In order to find out whether this submaxillary eye was the left 
one and if so, how it had come to occupy such a curious position, 
and further whether it was also internally of normal structure, two 
series of transverse sections were made, one of the lower jaw and 
one of the remainder of the head. 
It appeared that the left eye had indeed been shifted downward, 
that the structure was quite normal and that a well developed 
optie nerve and strong muscles, attached to the sclerotic in the 
usual way, rendered it possible and even very likely that the eye 
had functionated. These nerve and muscles originated from the upper 
part of the head; the nerve came forth from the brain in the usual 
manner, perfectly symmetrically with the nerve of the right eye; 
the muscles proceeded caudally quite symmetrically with the muscles 
of the right side. Nerve and muscles however followed the normal 
way over a short distance only, they soon bent downward and 
descended through the head to the lower jaw, right through the 
buccal cavity along a stalk connecting the upper and lower jaws 
and situated just before the tongue. The nerve’ was surrounded by 
the four straight eye-muscles; the two oblique ones were situated 
orally of the first-mentioned complex of muscles and nerve. 
From this stalk the whole complex proceeded downward right 
through the lower jaw to the place where the eye was found. 
Besides nerve and muscles also a blood-vessel descended, which 
entered the eye together with the nerve. 
Of the bony roof of the mouth, which this complex of muscles 
and nerve had passed, the entopterygoid, lying between the paras- 
phenoid and the palatine, was laterally and posteriorally shifted, so 
that it no longer bordered on the parasphenoid. A muscle, the 
arco-palatine adductor muscle, was much lengthened .and behind the 
muscle-nerve complex bent from the entopterygoid to the parasphenoid. 
For the rest little change had occurred in the upper part of the 
head. The place where the eye should have been, was filled up with 
