400 
Tapeworms of Birds 
Amoebotaenia sphenoides von Linstow. 
Occurrence. Warwickshire, Staffordshire, Shropshire, Worcester¬ 
shire and Lincolnshire. 
Attachment of Scolex. When drawing up a previously published 
account (8) of the anatomy of this tapeworm, it was found impossible 
to obtain sections of the scolex in situ in the intestine and a description 
of its attachment had therefore to be omitted. Since then by great 
good fortune a series of sections was cut which showed this in detail. 
More incomplete and imperfect series confirmed the results obtained. 
Upon the death of the fowl, the scolex quickly releases its hold upon 
the intestine. In order to see its attachment to the best advantage, 
it is necessary to remove the alimentary canal of the fowl as soon as 
possible after death, allowing an interval of twenty minutes at most to 
elapse. The duodenum should then be opened quickly and, if the 
Cestode be present, a portion cut off and placed at once without previous 
washing in the fixative. If however the fowl be allowed to remain 
unopened for half an hour, or the intestine remain opened for five minutes, 
the worms will be found entirely to have released their hold and be 
lying freely in the lumen of the duodenum. Dipping the alimentary 
canal in water or salt solution also causes a complete relaxation. 
The scolex (PI. XXI, fig. 25) penetrates the usual distance into the 
wall of the duodenum, i.e. nearly to the submucosa. In this species the 
suckers play a more prominent part than in most. They are cup-shaped 
when in use and are all four attached to the intestinal epithelium. 
By their own pull and the weight of the body, the tissue inside them is 
dragged out into small tongues, projecting from the villus into their 
cavities, and forming small pegs upon which they apparently hang. Being 
unarmed, the result is a continuous pulling strain upon the epithelium, 
not a breaking and disintegrating strain as in Davainea dubius. The 
damage thus done by them is consequently less, although the constant 
strain causes the tongues of tissue to break off from time to time. The 
suckers appear to bear the chief burden of fixation, and, their hold 
relaxing under abnormal conditions and not being more or less per¬ 
manently fixed by hooks, the worm readily becomes detached from 
the duodenal wall. 
The rostellum, unless the worm be detached from the duodenal 
wall, is nearly always extruded. In this condition, the knob forming 
its apex is considerably less in diameter than the space between the two 
villi. The apex of the rostellum therefore lies against one or more villi. 
