128 ANIMAL PARASITES. 



this cylinder tlie Cysticercus lies. The posterior end of this 

 cylinder reaches to the retina, but the fundus of the vesicle of the 

 Cysticercus separates distinctly a little before it. Anteriorly the 

 longish vesicle diminishes in calibre, and runs, somewhat con- 

 stricted in the middle, into the neck region in front. The head 

 itself is situated about in the centre of the eye, and appears as a 

 whitish swelling, the true relations of which are concealed by the 

 enveloping cylinder, and from which various streaky, pseudo- 

 membranous rays run forwards and towards the lens." Still in 

 front of the body just described, #nd on the hinder wall of the 

 lens, lies a second body similar to a Cysticercus, as to which Von 

 Graefe was not perfectly clear at the time, but which might 

 possibly be a dead Cysticercus. Even in the first case, movements 

 could not be distinctly perceived, a circumstance which must be 

 explained by the position of the structure exactly in the axis of 

 vision, and by the fact that the sac referred to is itself in a con- 

 stant state of rocking motion, and consequently it is very difficult 

 to get a clear view of the independent movements of the worm. 

 Nevertheless, Graefe believed he recognised the undulatory con- 

 traction of the hinder portion (caudal vesicle) of the worm. 



During the continuance of the malady just mentioned, the 

 patient, who was afflicted with strabismus, arid on that account 

 sought Graefe' s advice, could still distinguish fingers at a distance 

 of several feet, but during fixation, the axis of vision was diverted 

 considerably inwards from the object. The patient could not 

 decypher the largest print even with magnifying glasses. The 

 other eye was sound. Tcenia solium was present ; but there was 

 no Cysticerci in other parts of the body. 



In No. 45 of the ' Deutsche Klinik' for 1856 (Sitzungsbericht 

 der Ges. fur wiss. Med./ July 21st and August llth, 1856) Von 

 Graefe reported upon a moveable Cysticercus celluloses in the 

 vitreous humour, which already began to exhibit turbidity in con- 

 sequence of the irritation to which the animal gave rise in it. 

 Von Graefe established a coloboma in the sclerotic coat, and after- 

 wards extracted the Cysticercus with great difficulty by incision of 

 the sclerotica. In this operation the caudal vesicle was torn off, 

 and the head and neck, which were seized by a serre-tete } could 

 only be got out after several attempts. Of the cyst only a 

 portion was removed. The suckers of the Cysticercus continued 

 to move for twenty minutes, under the microscope. The visual 

 power of the patient improved ; he could read large print, count 



