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origin and significance, yet so closely resemble the most characteristic 
lesions of the latter disease as to be almost indistinguishable, save to 
careful microscopical examination. 
To what extent the cystic worms which cause these appearances 
may be found in England, I am unable to say ; but in India, at any 
rate, they are very common, far commoner indeed than instances of 
true tubercle, which, fortunately for us, are but rarely to be met with. 
Wherever found, however, an ignorance of their true significance 
might easily lead to the destruction of large quantities of perfectly 
wholesome food. Anything affecting food-supply is a matter which 
is of interest to all, and this circumstance, together with the fact that 
the appearances are due to a curious and but little known phase in 
the life-history of these Entozoa, of the broadest general biological 
interest, may compensate the Society for the introduction of certain 
pathological details inseparable from helminthological studies, but 
which, by the avoidance of technicalities, I hope to make sufficiently 
intelligible to all. 
To a pathologist it would suffice to say that the appearances in 
question closely resemble those of miliary tuberculosis, but for the 
general reader it may be well to premise that these minute helminths 
reveal their presence to the naked eye as small greyish or yellowish- 
white nodules, from the dimensions of a pin’s head and upwards in 
size, scattered through the substance of the lungs and liver, and occa- 
sionally of the spleen. Any one who has seen a section of the last- 
mentioned organ, must have noticed the small whitish bodies known 
as Malpighian bodies. Now, the tubercles I am about to describe 
resemble these bodies so closely, that their detection in the spleen is 
a matter of the greatest difficulty, and this resemblance may serve as 
a guide to those searching for them in other organs. I have, indeed, 
often met with portions of sheep’s liver which might easily have 
been mistaken for a morsel of spleen to the casual glance of a naked- 
eye anatomist. The worms which give rise to these appearances in 
sheep and oxen are cestode embryos ; those that give rise to closely 
similar appearances in the solid viscera of equine animals are immature 
nematodes. The exact species in each instance is a matter of uncer- 
tainty, though I have little doubt that the cestode tubercles are 
mostly due to Tsenia echinococcus. 
The cestode tubercles found in ruminants are much more common 
in sheep than in oxen. Out of 110 sheep examined I found the con- 
dition under discussion to be present in the livers of 32 and in the 
lungs of 12. Unfortunately, I have no note of the relatively nume- 
rical proportion of its prevalence in oxen, but it is certainly far less 
frequently met with ; while the reverse is the case with cystic worms 
which have developed sufficiently to constitute definite cysts, and 
which are of course excluded from the above enumeration. 
The number of tubercles present varies greatly, from a few only, 
scattered at such rare intervals that it would be hardly possible to 
