2 FRANCIS H. WELCH. 
vouch for, and in a minor degree also among the same classes 
in parts of British North America ; also the post-mortem 
records of the Royal Victoria Hospital, Netley, illustrate 
examples of this parasite in invalids from India, Cape, Mau- 
ritius, Ceylon, Malta, and Gibraltar, generally solitary, 
occasionally more than one in the same host, and in indi- 
viduals where its presence was not observed during life, 
while on the other hand I can find no notification of the 
occurrence of the 7. solium among our wide-spread garrisons, 
and the same feature of comparative prevalence is shown in 
the preparations of the Netley Museum; and if to this we 
add the statement of Professor Aitken that it also “is the 
common tapeworm of the Continent,” it is clear that, acting 
up to our present knowledge, we must reverse the prevalent 
opinion and regard the 7. mediocanedlata as the common 
form and as the type of the genus. 
Owing to the parasite receiving so many illustrating ex- 
amples, ‘there is no lack of material in army life to work 
upon, and the result of an inquiry into its anatomy I have 
embodied in the present paper; some of the details are 
corroborative of previously made observations, others are 
opposed to.them, while on certain points inquiry has been 
further extended. 
The general aspect of the linearly arranged colony of flat 
white zooids embraced under the term “ tapeworm,” pro- 
gressing in size from above downwards, is too well known to 
need description, and hence we may pass over major naked- 
eye characters common to the genus to enter at once 
on those details to be noted in the species under considera- 
tion. 
Should we have an opportunity of examining specimens 
taken entire from the small intestines of the dead host we 
find that the actual length between individual colonies varies 
considerably, and chiefly i in proportion to the state of con- 
traction or otherwise of the component segments, ranging in 
fact from five to ten feet ; and it is to be observed as regards 
this range of total length that should there be vitality still 
existent, and the contractility of the tissues excited by im- 
mersion in alcohol, the extreme measurement may by this 
means be curtailed so as closely to approximate, or even 
reach, the minimum length of five feet. ‘The firmness of the 
segments resulting from this immersion in alcohol before 
muscular action has passed into the quiescence of death is of 
great assistance in making sections for microscopical exami- 
nations. It must also be noted that this contraction, which 
is mainly longitudinal in the colony, may modify somewhat 
