78 
Several other names 0 have been based upon the names of the hosts 
in which the parasites occur, thus intimating that they are viewed as 
distinct or probably distinct species. 
A number of names b have been based upon the organs in which the 
parasites occur. 
Fig. 126. — Adult Hydatid Tapeworm Echinococcus granulosus) . Enlarged. (After Leuckart. 1S80, 
743, fig. 316.) 
Fig. 127. — Hooks of Hydatid Tapeworm: a. from a hydatid; b, three weeks after feeding to a dog: c, 
from an adult; d, combined figures of a-c, showing the gradual changes inform. x600. (After 
Leuckart, 1S80, 736, fig. 315.) 
Quite a large number of names have been based upon modifications 
in growth, but to understand these we must consider the method of 
development. 
'When the six-hooked embryo (onchosphere) comes to rest in an 
organ, it graduallv increases in size. After a time it consists of a thick 
a Names based upon the names of hosts: Polycephalus hominis Zeder, 1800a; P. 
humanus Zeder, 1803a; Acephalocystis hum-ana Luedersen, 1808; A. suilla Luedersen, 
1808; Echinococcus hominis (Zeder, 1800) Rudolphi, 1810a; E. simise Rudolphi, 1810a 
( Hydatis erratica Blumenbach, 1805, renamed'; E. simise cynomolgi Oken, 1815; E. 
suis author? date?; E. girafse Gervais, 1847a; E. arietis E. Blanchard, 1S48; E. gir affix 
Diesing, 1850a; E. pardi Huxley, 1852 ?; 11 Acephalocystis macaci ?” Cobbold, 1861e; 
? Acepjhalocystis ovis tragelaphi Cobbold, 1861e. 
& Names based upon organs in which the parasites occur: Echinococcus cerebri Spier- 
ing, 1862; E. hepatis Scholler, 1862, and Kehlberg, 1873; E. process . rermiformis 
Scholler, 1862; E. lienis Ber. Krankenanst. Rudolf-Stiftung, Wien, 1867, and Kehl- 
berg, 1873; E. pulmonum. Huppert, 1875a; E. intracranialis Fricke, 1880a (E. inter- 
cranialisot Stiles, 1896, misprint); E. retroperitonealis Bitter, 1886a (E. retroperito nialis 
of Stiles, misprint); E. rnesenterii Surmann, 1891; E. subdi aph ragmal is-prseper itonealis 
Krasnoff, 1895a; E. cerebralis Perroncito, date? (probably based on “ Echinococchi 
cerebrali ” Perroncito, 1882, p. 172); E. subphrenicus Huber, 1896a. 
