80 
formation of secondary cysts is reported especially for man, and has 
been described under several different names.® 
In another variation in growth, found particularly in ruminants, 
the daughter cysts escape externally from the mother cysts. This is 
referred to as an exogenous formation; that daughter cysts may form 
Fig. 129. — Diagram of an Echinococcus hydatid: cu, thick external cuticle; pa, parenchym (germinal) 
layer; c, d, e, development of the heads according to Leuckart; /, g, h, i, k, development of the 
heads according to Moniez; l, fully developed brood capsule with heads; m, the brood capsule has 
ruptured, and the heads hang in the lumen of the hydatid; n, liberated head floating in the 
' hydatid; o, p, q, r, s, mode of formation of secondary exogenous daughter cyst; t, daughter cyst with 
one endogenous and one exogenous granddaughter cyst; u, v, x, formation of exogenous cyst, after 
Xuhn and Davaine; y, z, formation of endogenous daughter cysts, after Naunyn and Leuckart; y, at 
the expense of a head; z, from a brood capsule; evag., constricted portion of the mother cyst. 
(After R. Blanchard, 1886a, 426, fig. 257, slightly modified.) 
a Names applied especially to the variation found more commonly in man, usually 
with, endogenous formation of secondary cysts: Polycephalus hominis Zeder, 1800a; 
P. humanus Zeder, 1803a; P. echinococcus Zeder, 1803a; Echinococcus hominis (Zeder, 
1800) Rudolphi, 1810a; Liococcus Bremser, 1819a; Splanchnococcus Isevis Bremser, 
1819a; Echinococcus altricipariens Kuechenmeister, 1855a; Cysticercus echinococcus 
(Zeder, 1803) Kceberle, 1861a; Echinococcus hydatidosus Leuckart, 1863; E. endogena 
(Kuhn, 1830) Leuckart, 1863. 
