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The permeation of dissolved oxygen through membranes is an important phenomenon in many biological systems. The polarographic method of measuring oxygen provides a quick and accurate means of measuring the permeability of oxygen through many membranes, both in the gas phase and as dissolved oxygen. The oxygen permeability can be utilized as a means of estimating changes in the structure of hydrated membranes, especially hydrophilic polymer membranes and hydrated polymer gels.

Comparative chemical analyses show the aqueous humor of smooth dogfish has lower concentrations of urea and trimethylamine oxide than the blood plasma. Freezing-point depression determinations demonstrate that the aqueous humor has a correspondingly lower osmotic pressure. It would appear that water entering the aqueous humor from the plasma is moving against an osmotic gradient.

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To determine the toxicity of CG, CK, and AC to goats and the respiratory behavior of goats when exposed for short periods, in order to calibrate this animal for use in field studies of surprise effects.

Wide acceptance has been given to the expansion of "blood volume" in the presence of an arteriovenous fistula. Most clinical measurements have been made with abbreviated technics of T-1824 dilution. In the present study, carried out on casualties of the Korean War, significant expansion of the "rapidly distributing T-1824 and effective circulating albumin" were found in 31 patients with traumatic arteriovenous fistulas. Analyses of dye disappearance slopes, prolonged studies with labeled albumin and dye infusion have been used to investigate the dynamics of these measured expansions.

To the Editor: —It is evident from Dr. Arthur Keeney's guest editorial (Arch Ophthal70:739, 1963) that he has not fully appreciated the outstanding results Frederick Ridley is obtaining in the treatment of corneal pathology with scleral contact lenses. The Ridley scleral lens is not to be confused with the haptic lenses the American ophthalmologist knew 10-20 years ago and found unsatisfactory. Nor is it to be compared with the corneal contact lens in such widespread use today for simple refractive error and low astigmatism. The Ridley lens represents an entirely different concept of design, manufacture, and fitting, one which demands an unremitting and fastidious attention to detail and the constant and close supervision of an experienced ophthalmologist. When first I heard Frederick Ridley's results with scleral lenses in cases of difficult corneal conditions I was somewhat skeptical. I remembered the days of haptic lenses with opticians and other laymen

Luminance thresholds for downward moving contours were measured under several conditions of adaptation. Included was one condition which desensitized visual mechanisms responsive to downward motion. Another condition exerted equal effects on both up- and down-sensitive mechanisms. Thresholds for moving contours were unaffected by exposure to contours which moved in the opposite direction. This indicates that the perception of motion does not depend upon the relative activity in oppositely tuned, directionally selective visual mechanisms.

The rapid curative action of sulfanilamide in cases of inclusion conjunctivitis in infants and adults was described in two previous reports. 1 It was found that infants responded in the first few days of treatment and were usually cured within a week. In adults the papillary type of the disease responded equally rapidly, but in cases with predominant follicular hypertrophy several weeks were required for the conjunctiva to return completely to normal. The inclusion bodies characteristic of the disease could not be found after the first few days of treatment. There were no recurrences in cases in which the treatment was continued six days or longer. Local therapy with 0.8 per cent sulfanilamide solution produced temporary improvement in 1 of 2 cases but failed to effect a cure. In spite of the demonstrable efficacy of the administration of small doses of sulfanilamide over a comparatively short period in curing inclusion

Most ophthalmologists in their everyday practice undoubtedly frequently see lesions of the eye that are directly or indirectly due to trauma. In treating these conditions one is apt to think of them as individual problems, yet many cases have a common background of failure in preventive measures that might have lessened the possibility of injury and of inadequate or improper treatment once the eye had been traumatized. All of us think of the combat phases of war as injury on a man-made epidemic basis. In many respects this is true, but in this mechanized age, with the employmentof many chemical and physical methods in the nation's economy as well as mechanized devices, trauma in its various forms is an everyday experience. During World War II approximately 80 per cent of the cases of blindness that occurred could be directly attributed to various types of trauma. Although I have

During the past six years numerous types of incompletely epithelized postenucleation implants have been developed. This was begun by Ruedemann1and was continued by Cutler2and others.3Reviews of this development have been presented.4The movement of most of these implants is practically complete and is far superior to the older glass, gold or bone ball implants, wherein the movement of the stump was transmitted to the shell by means of friction between the conjunctiva and the outer scleral shell. This union usually resulted in a great deal of slippage between the two elements, and therefore only minimal movement at best, while the movement of the partially covered im plants is transmitted directly to the overlying shell by means of a peg or as the result of use of a one piece implant. Because the psychological advantages of com plete or nearly complete motility of an

Ophthalmologists in a national survey reported case histories of 14 eyes lost or blinded in patients wearing contact lenses. All of the eye losses were due to infections, four of which were by fungi. There were 157 other eyes permanently damaged and 7,607 with reversible changes. These physiologic and pathologic eye changes indicated the medical problems of diagnosis, treatment, and routine follow-up of these patients.