74 Dr Y ule on the Effects produced by the presence of the 
from the atmosphere, in the temperature of the human body ; 
exposed to the action of the gastric juice, and process of diges- 
tion, without apparent injury ; whereas, under the circumstances 
natural to this race, the ovum would have been attached to some 
plant, probably under water, at the usual temperature of the 
atmosphere. Indeed this patient attributed, and with proba- 
bility, his severe illness to his occasional drinking of the water 
of a neighbouring ditch, in which he might have swallowed 
either the ovum or the larva in its early state ; for the larva of 
certain Tipulae and also Phalense inhabit the water ; but when 
they arrive at the winged state, are readily drowned, if immersed 
in this their original element. So very opposite are the econo- 
my and habits of the same individuals in these very different 
periods of their lives ! 
4. But whatever difficulties attend our inquiries into the his- 
tory of this part of nature, the evidence on which it is founded 
is so far conclusive. It would seem likely however, that the phy- 
tivorous are less adapted to live, and attain their perfect state 
in the cavities of the living body of man and other animals, than 
the carnivorous larvae ; but we are too little acquainted with 
this interesting part of physiology, to pronounce with confi- 
dence. Indeed, since the times of Bedi, Haller, and Mead, 
little progress has been made in it, although some valuable facts 
have been incidentally noted, bearing on the subject. In an early 
volume of the Edinburgh Medical Journal, Dr Reeve of Nor- 
wich mentions a case of the larva of the house-fly ( Musca 
domestica ) being voided by a girl, after it had been the cause of 
much distress. An instance is stated in the useful and popular 
work of Messrs Spence and Kirby of several beetles (the Tene- 
brio molitor) being vomited by a boy ; the larva of this insect 
is the meal-worm of the country people, now little known from 
the general custom of using wheaten bread, prepared by the 
baker, instead of cakes, for which it was formerly necessary to 
lay up stores of meal. 
5. As to the medical treatment in cases of this kind, it is some- 
what consolatory to think that Nature herself frequently reme- 
dies the evil. Sooner or later the period of the final evolution 
of the insect arriving, and it being then no longer capable of 
living in its first situation, and of being nourished by the ani- 
