130 
in order to prevent as much as possible dislocation of the retina, 
viz. formalin 5°/,, glacial acetic vinegar 1*/,—’/, °/,. 
Subsequently the head was deprived of skin, beak, lower-jaw and 
occiput, frozen on the freezing-microtome and cut through parallel 
to the horizontal plane as far as the middle of the two pupils. It 
was then thawed, dehydrated in alcohol, decalcified and embedded 
in celloidin or parts of it in paraffin. The sections measured 10—30u 
in thickness. 
From the Anatonucal Institute of Leyden. 
