552 OCCURRENCE AND RESULTS OF CYSTICERCUS CELLULOSE. 



Graefe and Samisch on the diseases of the vitreous humour 1 and 

 retina, 2 I am convinced that my opinion was perfectly justified. 

 What is here given us is little less than a complete history of the 

 bladder-worms inhabiting the vitreous humour, and an adequate de- 

 monstration is given of the fact that these worms originate in the 

 subretinal membranes. 



In ophthalmoscopic examination the bladder-worm appears first 

 as a bluish-white, sharply defined body, and lies behind the retina, 

 so that the vessels of the latter extend over it. The bladder is easily 

 flattened by pressure, and exhibits the head as a clear spot shining 

 through. The latter is always invaginated, and never protrudes, 

 although the wall of the bladder constricts and dilates in an un- 

 dulating fashion. In many cases the worm moves away from its 

 original seat, loosening and disturbing the retina over an increasing 

 area. The vitreous humour is also penetrated by delicate membranous 

 opacities, which extend in front of the bladder like a veil or curtain, 

 with dark folds and stripes. Subsequently the retina is partially 

 destroyed by the increasing pressure of the bladder, so that the latter 

 falls forward into the vitreous humour. Sometimes one sees how the 

 neck with the head is protruded through the opening. When the 

 whole worm has broken through into the vitreous humour, its former 

 seat may still be seen as a discoloured spot of irregular form, while 

 the point of rupture can be but rarely seen with any distinctness, 

 owing to the turbidity of the vitreous humour. 



If frequent change of position, or copious discharge of fluid under 

 the retina, have led to an extensive or total loosening of the same, the 

 Cysticercus remains lying where it was, and does not break through 



into the vitreous humour. The bladder then 

 becomes encapsuled by connective tissue, 

 which gradually acquires a firmer nature, 

 and may finally undergo a partial ossification. 

 On sections of such eyes the bladder 

 is seen lying between the choroid and the 

 retina. Round about the worm, or over 

 the whole extent, the retina is much thick- 

 ened by proliferated connective tissue, and 

 has fused with the capsule, or is sometimes 



FIG. 298. Subretinal Cysti- . L ' ... 



cercus in the eye, after v.Wecker atrophied. Similarly the choroid IS SOme- 



(nat. size). times also involved in the exuberant growth 



of connective tissue. 



Less frequently there is formed round the parasite, at an early 

 stage, an envelope of delicate vascular connective tissue, which raises 

 1 Bd. iv., p. 709. 2 Bd. v., p. 708. 



