CESTODES 521 



The geographical distribution of the bothriocephalus is a limited one. It 

 has been frequently noted in the Eussian Baltic provinces, in the northeastern 

 part of Sweden, in Denmark, East Prussia, Kussia and Poland. Its presence 

 has also been determined in the coast districts of Belgium, Holland, northern 

 France, and in Ireland. It is remarkably common in the western parts of 

 Switzerland, on the shores of Lake Geneva and Lake Neufehatel, and in those 

 parts of Prance and Italy bordering upon Switzerland. The parasite is often 

 seen in Japan. It is found sporadically in Germany, in Ehenish Hesse, Berlin, 

 Nuremberg, Munich and Greifswald, and has been found in North America. 



Of the other bothriocephali we find in man the 



Bothriocephalus cordatus, Leuchart, 1863. 



This variety is characterized by a short, broad, heart-shaped head which is 

 supplied with two suctorial disc-like pits. The parasite which is chiefly found 

 in various mammals in Greenland and in Iceland is occasionally also noted 

 in man. 



The tape-worm described as 



Bothriocephalus cristatus, Davaine, 1874, 



may possibly represent only another form of the bothriocephalus latus. Its 

 head is characterized by two extremely long, helmet-like points. 

 Of another variety of bothriocephalus, 



Bothriocephalus Mansoni, Coblold, 1883, 



only pleroeercoides have as yet been observed, and these apparently wander in 

 the body of man. They finally reach the skin, and there cause abscess forma- 

 tions, or they enter the urinary passages whence they are discharged with the 

 urine. 



Bothriocephalus grandis, Blanchard, 1894. 



Ijima and Kurimoto have observed a bothriocephalus previously unknown, 

 which lacks a head portion. It measures in breadth, anteriorly, 1.5 mm., pos- 



FiQ. 49. — Bothriocephalus Grandis. Proglottid and Ovum. (After Ijima and Kurimoto.) 



feriorly, 25 mm. The proglottides are extremely short, and are supplied with 

 a double genital apparatus. 



The ventral surface contains the genital pori, anteriorly the mouth of the 

 cirrus and that of the vagina, behind these that of the uterus. The ova possess 

 a lid, are thick-shelled and brown; their length is 0.063 mm., their breadth, 

 0.048 mm. They contain a mulberry-like mass of fine globules. 



There can be no doubt that parasites infect some persons in whom no 

 deleterious influence upon the health is manifest. The patients in such cases 



