CASE 44.--Hedw. von L--, æt 10, came under treatment in April, 1874, for convergent squint on the left side which arose in her seventh year, with occasional alternation. Emmetropia, determined with atropine on both sides and good visual acuteness. Diplopia was present at the commencement of the squint. Patient can only be rendered conscious of double images by the help of a red glass and vertically deviating prisms. Double tenotomy of the internal recti effected a normal position, and at the end of December, 1874, the continuance of the same could be proved as well as binocular fusion with prisms. At the beginning of 1880, I was informed that from time to time periodic squint had occurred with diplopia. In the middle of March, I had an opportunity of seeing the young lady. Myopia 2 D. had meanwhile developed on both sides, visual acuteness almost = 1. The position of the eyes was perfectly good, slight convergence occurred during covering, homonymous double images with a red glass which, at a distance of 5 m., were joined by a prism of 8°; stereoscopic fusion was not perfectly certain. A true squint could not be proved. On April 3rd, as patient stopped for a few hours on her journey through, a striking convergent squint of the left eye was seen. The deviation amounted to 4 to 5 mm. Single vision existed at a distance of 15 to 20 cm., then homonymous double images appeared, which did not correspond to the objective deviation; the double images were however corrected by a prism of 6° (base outwards) for an object 5 m. distant. We cannot conclude the consideration of the operative treatment of convergent squint without once more returning to the relation between the line of vision and the position of the cornea. The angle [Greek: a] still deserves mention in a few thankful words--_hic mihi angulus praeter omnes ridet_--it is a very useful guide in tenotomy. In tenotomy we may count as gain the apparent divergence which it causes in hypermetropes who do not squint. We obtain a perfect cosmetic result, while a convergence, objectively determinable, but not otherwise easily visible, continues to exist. It would be folly to exceed this; and for cases where binocular fusion does not exist, and where diplopia is not present, to wish to remove this covered convergence due to the angle [Greek: a], the cosmetic result would be impaired by it.