GENERAL PROPERTIES AND ACTIONS OF THE VENOM. 65 



siderable variation in the rapiditj^ of advance of these symptoms), until the 

 eye protruded about 2 or 3 mm. from its socket and the cornea assumed a 

 gray-white color. This appearance was observed as early as 3 hours after the 

 injection of venom. 



If the condition continued to progress the gray-white of the cornea and 

 sclera now turned red and gradually assumed a dark red color. At times the 

 blood which had collected in the tissue about the eye-ball would break through 

 the conjunctiva and a more or less free oozing of blood about the eye would be 

 the result. Whether this breaking through of the blood was due to the pressure 

 exerted by the blood within the eye-socket, or whether it was due to external 

 trauma, we can not state. It is certain that when the cornea has become abso- 

 lutely opaque the animal is blind, and, in view of the blindness and the unusual 

 prominence of the eye, the mouse might easily rub the weakened eye against 

 some object and thus injure the conjunctiva in moving about the cage. 



In those cases in which the condition progressed only as far as the stage 

 of corneal opacity, the animal seemed to be able to regain its vision after sev- 

 eral days; but when the condition progressed to the stage of subconjunctival 

 hemorrhage or actual oozing of blood, the eye-ball was lost, although the ani- 

 mal might otherwise recover from the injections. The stages of healing, either 

 the return to normal or the disappearance of the protrusion and hemorrhage, 

 progressed usually very rapidly, so that while the lesion usually reached its 

 maximum severity between 12 and 24 hours after the injection, no external 

 evidence of the lesion could be noted at a period 3 days after the injection. 



It remained to be determined whether these macroscopic appearances 

 represented a pathological condition within the eye-ball or within the perioc- 

 ular tissue. We removed the eye-ball and periocular tissue of several mice 

 which had been injected with venom and which showed the various stages of 

 the conditions described above. These eyes were sectioned and studied micro- 

 scopically. 



The microscopic examination of these tissues showed that in the earliest 

 stages of the condition there was a slight extravasation of blood in the loose 

 fatty tissue around the optic nerve, usually at some distance from where it 

 entered the eye-ball, but no evidences of any intraocular lesions were observed. 

 In later stages the hemorrhage in the periocular tissue became more evident 

 and spread forward in close proximity to the optic nerve and also laterally in 

 the fat tissue. Gradually the blood worked around the eye-bulb and appeared 

 under the conjunctiva. At no time was any blood found inside the eye-bulb. 

 The only abnormal condition within the eye consisted in the forward pressing 

 of the lens until it almost touched the posterior surface of the cornea. It is 

 possible that this condition of the lens was due to the manipulation of the eye 

 during its removal, or, perhaps, to the osmotic movements of the aqueous 

 humor during the fixation of the tissue, since it was noted in only a few of the 

 eyes examined. 



These ocular lesions in mice that follow the injection of venom are, there- 

 fore, confined to the periocular tissue of the orbital space. There occurs first 



