500 



pulex) bj- Hamanii (1889, pp. 7-9) and V(in Linstinv (l>ii)2A. p. 

 338); antl in c'Ope>;i(ifls (Cyclnps agails and C. pulihellus by 

 Mrazek 181*1). 



Ttius, chickens ai-e kuuwij to becunie iiiLecied uiiii 

 one tapeworm llirou^h eating slugs (Liniuxj. They arc 

 supposed to become iiilecUHi witii a second thiougli 

 eating snails (Helix); by a third thiongh ealing Hies, 

 and by a fourth through eating earthworms. 



Ducks are known to become infected with twowonn^ 

 (hrougli swallowing fresh-water crustaceans, and art- 

 supposed to become infected with tliree other tai)e- 

 worms in the same vvav; another tapeworm is supposed 

 to be transmitted to them through flies. 



Geese are suppo'sed to become infected with five 

 species of tapeworms by swallowing small fresh-watei- 

 crustaceans. 



Nothing is known in regard to the source of infec- 

 tion of the tapeworms of ])igeous and turkeys, l)ut in- 

 vestigations in this field should be based upon the tape- 

 worms of chickens. 



THK RELATION OF THE TAPEWORMS OF WILD BIRDS 

 TO THOSE OF THE DOMESTICATED FOWLS. 



Only two of the chicken tapeworms (Dr. infundibuli 

 formis and T. malleus) have as yet been recorded for 

 wild birds, but the majority of the tapeworms found 

 in the domeslicnted ducks and geese are also recoi'ded 

 from closely allied wild birds; besides these forms, 

 however, many species have been described in wild 

 birds which are not known to occur in the domesti- 

 cated fowls. (See chart at end of text.) This renders 

 the economic side of the question of avian cestodes ex- 

 ti-emely cnmitlicaled and demands a thorough study of 



