Account of a Filaria in a Horse's Eye. 289 
frightened, it opens the lid of the left, as well as widens the open- 
ing of the right eye, which continues disclosed but a short time 4 
however, this gives an opportunity for inspection for five or six 
seconds of time together, and the blows must be repeated to keep 
the eye open when a person wishes to-have a longer time for in- 
spection.” 
The similarity of this case to the one now exhibiting, is too 
obvious to need remark. In all their essential points there is al- 
most an exact correspondence, viz. the size, color, shape and ap- 
pearance of the worm; its incessant motion; the cloudiness of 
the aqueous humor, and the partial blindness of theeye. In the 
case, however, reported by Mr. Hopkinson, the worm appeared 
to excite more sensation in the eye, and consequently. produced a 
higher degree of inflammation. This no doubt was occasioned 
by its passing through the iris, and coming in contact with the 
expansion of the retina and the delicate ciliary processes ; where- 
as in the present case, the animal is confined exclusively to the 
anterior chamber of the eye, which is comparatively insensible. 
Origin. —It is a singular fact that some of the first physiolo- 
gists and helminthologists of the day, attribute the origiv of in- 
testinal and visceral worms to spontaneous generation. Such is 
the opinion: of Muller, Bremser, and most of the German physi- 
cians. The opinion of Linneus, that they were terrestrial or 
aquatic species, taken in with food or drink in the form of ova or 
germs, is now exploded, for, with the exception perhaps of the 
Fi. , we do- not find the same species of worms which 
infest animal bodies, out of them. Indeed, Cruvelhier lays it 
po? alerts axiom, that worms, like the intestinal and vis- 
othe? animaié;. unless discharged from them ; and the con- 
verse of this he holds to be no less true, viz. thet no terrestrial 
or aquatic worms have ever been met with alive, in the bodies of 
men and other animals, unless they had been very recently intro- 
duced into them. We might then conclude, with confidence, that 
worms do not originate from without, but are generated within 
the body, were it not contended that ‘these animals may have 
been introduced ab erterno, but that in consequence of a change 
of situation and nutriment, their forms and characteristics are al- 
tered, as plants and animals are under similar circumstances, and 
as neuter bees are made prolific, on the loss of the queen bee, by 
