DR. CHISHOLM ON THE MALIS DRACUNCULUS. 101 
ture of the lymphatic system is adverted to, the capacity of its 
vessels not permitting the return of the ova, once deposited in 
the cellular membrane, into the circulation by absorption. 
In general, with respect to objections which may be pro- 
posed, it may be observed, that all substances endowed with 
life, and even the essential oils of animals and vegetables, are 
not soluble in the human stomach. But the oils, although they 
are incapable of solution in, are capable of mixture with the 
chyle, and pass into the circulation with it. Many familiar 
proofs of this exist among animals. If, therefore, the globules of 
oil enter into the circulating mass, and become even a part of 
the secretions --milk, urine, and perspirable matter, more espe- 
cially of animals — it does not require much stretch of faith to 
give admission to the fact, that the ova of certain insects, al- 
though indigestible, from their vitality, in the human stomach, 
mix with the chyle without losing their vitality, and with it en- 
ter into the blood, and are deposited in various organs, accord- 
ing to the distribution of the vessels which circulate them. 
Many of these ova are more minute than the globules of oil, 
and, therefore, can experience no more obstruction than they do 
in their passage from the stomach to the organ or part in which 
they are deposited. In truth, were we called upon to explain 
the manner in which worms find their way into the teeth, the 
eyes, the urine, the liver, the pericardium, the kidneys, &c., in 
no other way could we rationally account for the phenomenon, 
than by saying, that the ova of these worms are received into 
the stomach with the food or drink, mix with the chyle, en- 
ter into the blood in a living state, and are deposited in various 
organs, where they are evolved, and produce living insects. 
We can in no other way explain the surprising facts of worms 
found in the eggs of fowls, and in the intestines of a human 
foetus before birth. We must believe that their ova have passed 
through the circulating vessels of the mother, and by this means 
been conveyed to the foetus. The capacity of the stomach 
during life to resist the action of the gastric fluid, but the loss of 
this capacity with the loss of life, is a satisfactory enough proof 
that substances endowed with vitality may exist in the stomach 
without suffering by the action of the gastric fluid. 
Another analogical proof, equally satisfying, and infinitely 
more surprising, as it relates to the pertinacity with which the 
ova of insects maintain their vitality, may be drawn from the 
fact, that the most intense heat does not deprive them of it. 
(See “ Good’s Anniversary Oration on the Structure and Phy- 
siology of Plants and Animals,” p. 30-34, an. 1808.) 
The pthiriasis interna is infinitely more singular in its ori- 
