82 BOARD OF AGRICULTURE. 
this condition the creature has a flask-shaped form. The neck 
tapers gradually from the bladder to the head, and is divided 
transversely into a series of many short joints. The head is 
but little enlarged, bearing four suckers, as usual, and in the 
Figure 60. 
center has a proboscis, surrounded by two rows of hooks, con- 
taining from sixteen to twenty-four pairs. Sometimes there 
are found in large bladders of this kind afew secondary blad- 
ders attached to the inside of the large one, produced by a 
process of budding, somewhat as in the water-brain, or cw@nu- 
yus. This parasite, as thus characterized, was formerly sup- 
posed to be a distinct and peculiar species, and received the 
name of “ Cysticercus tenuicollis,” or slender necked bladder- 
worm. Recent investigation and experiments have, however, 
proved it to be only the young or larval condition of one of the 
common tape-worms of the dog (Tenia marginata). Blad- 
der-worms of the same kind are found, though less commonly, in 
cattle and horses,as well as in pigs, monkeys, and many other 
animals, and very rarelyin man. Owing to the large size to 
Figure 60. Diving bladder-worm, from a sh i 
eep; natural . 
Home, after Thudichum. : Pe oo 
Figure 61. Head of Tenia ‘git .! ; 
i Se es iia ana enlarged. Hearth and Home, after 
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Hearth and 
