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streaks cavities arise and according to Borkr they are transformed 
into true somites. After the stalks of the eye-vesicles have been formed, 
cells grow from the wall of these somites against the capsule of 
the eye-vesicles in order to form the eye-muscles. Borke observed 
that the musculus obliquus superior and the musculus rectus externus 
originate from the wall of these somites. The same has been observed 
by Miss Prarr in Selachians for all eye-muscles. 
How shall we imagine now that all this took place in our abnor- 
mal eel, related to the Muraena? When the eye-vesicle evaginated 
it probably did not grow laterally, but forward and downward. It 
reached the anterior mesodermic mass, which it pierced in growing 
in a forward and downward direction. It passed the place where 
entoderm and ectoderm grow towards each otber and finally came 
to lie against the ectoderm, more particularly the ectoderm from 
which later the skin of the lower jaw is formed. This latter reacted 
on it by forming a lens and a cornea, which is in itself very 
remarkable but not impossible, since the experiments of SPEMANN, 
Lewis and others have shown that at any rate in Amphibians 
lenses may be formed from the ectoderm in very unusual places. 
It still remains to be explained how the eye-muscles found their 
way towards the eye in the lower jaw. This will also have happened 
at a very early stage in the development of the eye, immediately 
after the formation of the stalk of the eye-vesicle. This latter had 
then been little shifted aside yet. The cells derived from the wall 
of the somites of the head then laid themselves, as in ordinary 
cases, against the capsule of the eye-vesicle and were carried along 
its unusual course through the anterior and inferior part of the head, 
while as in a normal case they developed to muscles. 
Leyden, February 1917. Histological Department of the 
Anatomical Cabinet. 
