The insertions of the extrinsic ocular muscles in the dog and cat show certain common features such as splitting of the insertion of the ventral obliquo, the direction of the line of insertion of the dorsal and ventral obliques and the division of the retractor oculi into four fasciculi. There are, however, some differences between the dog and cat as regards to the insertion of the dorsal oblique, the line of insertion of the medial rectus, the insertion of each of the four fasciculi of the retractor oculi and the lengths of the horizontal and vertical diameters of the cornea.
In the dog and cat the splitting of the insertion of the ventral oblique and of the dorsal oblique in cat, the direction of the line of insertion of the tendons of the dorsal and ventral obliques, the distances of the recti from the corneal limbus, and the complete divis¬ion of the retractor oculi muscle into four fasciculi are characteris-tic features from the sheep and goat.