14 
THE COLORADO EXPERIMENT STATION 
TAPE WORMS 
DESCRIPTION.—So far, only round worms, possessing a complete di- 1 
gestive tract and distinct sex, male and female, have been discussed. 
The tape worms differ from the round worms, in that they have no 
digestive tract, and both sexes are in the same individual. The tape worms 
all live in their adult state in the intestinal tract and absorb through their 
integument, nutrients taken in and digested by their host, thus robbing the 
host of food nutrients. The species studied in this laboratory was from 
chickens, and is the Taenia infundibuliformis. Its natural size is represented 
Fig. '7 
Figure 17.— Taenia infundibuliformis (tape worm) (from the intestines of a 
hen), natural size, a, head; b, the segments. 
in Fig. 17. The worm is white; the head is scarcely as large as a pin head 
and is provided with four sucker discs and a circle of hooklets. By these 
means, the worm holds to the mucous membrane of the first portion of the 
intestines. Following the head, there is a short unsegmented neck, which 
is narrower than the head. From this there is gradually developed segments 
which become a trifle longer and wider as the distance from the head grows 
greater. A short distance from the neck the segments become mature, that 
is, provided with fully developed sexual organs ready for fertilization. Each 
segment is a hermaphrodite, being provided with both male and female gen¬ 
erative organs. At the end of the chain of flat segments we find one or more 
ripe and filled with fully developed eggs. These segments as soon as ripe de¬ 
tach themselves and pass out to the ground with the feces, to contaminate 
water and feed and be again taken up by other birds. Other segments now 
develop in a like manner and the process goes on almost indefinitely. 
CONDITION PRODUCED.—If a hen be infested with large numbers of 
this worm, it is robbed of much nutrient material and becomes unthrifty. 
As a result of their irritation, the worms cause a loss of appetite, derange¬ 
ment of digestion, catarrhal condition of the bowel and loss in egg produc¬ 
tion. In feces of birds infested by tape worms- will be noted occasional seg¬ 
ments of the worms. These will be upon fresh feces and if observed closely 
or placed in warm water will be seen to possess the power of contraction and 
expansion as they change their shape. 
TREATMENT.—A few teaspoonfuls of a decoction of pumpkin seeds 
usually rids the intestinal tract of these worms. Powdered areca nut as pre¬ 
scribed for round worms may also be used. 
