22 FRANCIS H. WELCH. 
particles. On the separation of the segment from the parent 
stem the uterus and ovarian passages are opened up, and a 
free outlet for the eggs in the upper half of the segment is 
thus provided, highly suggestive of the rupture of a mature 
spore case,! while those in the lower half would also 
escape through the rugged aperture from the muscular 
contraction of the freed segment soon after extrusion from 
the host, or be set at large by the subsequent disinte- 
gration. 
The absence of an intestinal canal, and the restriction of 
the function of the suckers to anchoring merely, necessarily 
involves the absorption of nutriment by the body generally, 
doubtless obtained from the ingesta of the host. What, 
however, is the function of the water-vascular system in this 
parasite colony? Is it at allexcretory? and if for the purpose 
of conveying a fluid within for respiratory purposes, then, 
considering the conditions under which the colony is placed 
in the intestine of the host, and the patulous character of the 
lowest and largest channels, would not the taken-in fluid 
from the intestinal canal officiate also for nutritive purposes ? 
Certainly the inference is, that in this instance these tubal 
ramifications would act in both capacities. 
What may be the especial office of this parasite colony in 
the scheme of the universe is a difficult problem to solve. 
The neglect of strict sanitary precautions in our food and 
drink supply is unquestionably their gain, and the loath- 
someness of harbouring such creatures greatly induces to 
respect for preventive measures, and assists in their enforce- 
ment. There is no reason to doubt that we have the means 
within our own hands to rid our bodies of all chance of 
becoming the hosts of these zooids, and they certainly stand 
to us in the light of avengers of neglected laws. But what- 
ever may be the solution, there can be no question of the 
remarkable adaptability of each zooid in its anatomical details 
to the conditions under which it is placed, and for the repro- 
duction of its kind. Assuming that each ovarian gland pro- 
duces 200 ova, each zooid would develop 8800; and on the 
basis that the colony consisted merely of 800 segments (that 
which we can count in a colony, but which is very much 
under the mark; for, as far as we can judge, reproduction of 
1 The Bothriocephalus latus (Cobbold’s ‘ Entozoa,’ p. 298) appears also 
to discharge the eggs “ by the bursting of the over- ended uterus of the 
mature joint.” It also ‘is very subject to malformation, and has ‘‘ a well- 
defined internal membrane separating the central visceral mass from the 
surrounding external parenchyma of the body ;” points corroborating 
others in the natural connection between the two parasites. 
