ADRENERGIC NERVES TO THE EYE AND ITS ADNEXA IN RABBIT AND GUINEA-PIG,

The distribution of adrenergic nerves to orbital and ocular structures in rabbits and in guinea-pigs was studied with the sensitive and specific fluorescence method developed by Falck. Considerable species differences were found, especially in the irido-corneal angle, which in rabbits contains few varicose adrenergic fibers V.A.F., but in guineapigs many. In both species, V.A.F. were found in the cornea, in the dilator and sphincter pupillae as well as in the iris stroma, at the ciliary epithelium, in the ciliary muscle, and in the chorioid. In the chorioid, distribution is densest in those parts that correspond to the areas of the retina that have the highest visual acuity. In rabbits, the vascular nerves in the iris have an unusual distribution throughout the inner part of the perivascular sheath in some mediumsized vessels, they also reach the intimal layer. An adrenergic innervation of the smooth musculature outside the ocular bulb was found in the tarsal muscle, in the arrectores pilorum, and in that of the tarsal sebaceous glands. No V.A.F. were found around the acini of the lacrimal gland or in the optic nerve. Author