44 PROCEEDINGS OF THE NATIONAL MUSEUM. vol. 55. 



Location. — In small intestine of primary host. In central nervous 

 system, brain or spinal cord, of secondary host. 



Localities. — Greece, Germany, Switzerland, England, France, Italy, 

 Ireland, Holland, Scotland, Austria, Denmark, Iceland, Argentine 

 Republic, Sardinia, South Australia, New Zealand, German South- 

 west Africa, India, Hungary, Cape Colony, Chile, Spain, Shetland, 

 Algeria, United States. 



Life history.— Eggs developed by the adult worm in the intestine 

 of the primary host pass out and are ingested in contaminated food 

 or water by the secondary host. In the digestive tract an embryo is 

 released and bores its way through the tissues and into the blood 

 stream. An embryo which attains the central nervous system will 

 develop and form a coenurus which, unless removed by surgical inter- 

 ference, ultimately kills the host annual. The embryos which do not 

 attain the central nervous system begin development, but very soon 

 die and undergo degeneration. On the death of the host animal, as 

 a result of the pressure of the parasite or from other causes, if the 

 developed bladderworm is ingested by the primary host, part, or 

 possibly all, of the heads attached to the bladder may develo]> seg- 

 ments and form the strobilate worm. 



The writer (Hall, 1910) has previously stated that the dog is the 

 only known host of the adult Multiceps multicej)s. Sinco thai time 

 two records from the coyote (Hall, 1911; Hall, 1912), as a res ilt of 

 experimental feedings, have been published. The writer also stated 

 that h(i had not found the record of the adult worm in Alopex laiopus 

 {Canis lagopvs) credited to Mobius by Railliet (1893a). Since then 

 the record by Mobius (1874) has been for.rid, but it does not app >ar to 

 be an acceptjible record of Midtice'ps multiceps. The woims in ques- 

 tion V ere 55 to 65 mm. long and had gravid segments, and unless we 

 assume that these figures are an error for 55 to 65 cm., they can not 

 be considered as M. multiceps. In other respects the figures agree 

 fairly well with 31. multiceps — 95 to 113 segments ; head 800 ]i. wide ; 

 a double crown of 26 hooks, the large 160 pi. long and the small 120 ^ 

 long; the segments quadratic two-thirds of the distance from the 

 head and 2 mm. long and wide; the terminal segments 3 mm. long 

 and 2.6 mm. wide; uterus with 12 to 16 lateral branches; maximum 

 Qgg m.easurements 31.5 by 27.4 [jl. He states that the shape of the 

 hooks agrees witli those of M. multiceps. The size of the terminal 

 segments is not quite that of M. multiceps, but as there appears to be 

 some po'^sibility of error in the figures given for the strobila. there 

 may also be some in those for the segments. The writer further 

 stated, in the paper noted above, that there were no satisfactory 

 records of larval M. multiceps from man. Brumpt (1913) has since 



