INTERLAMELLAR FORMATION OF THE DAUGHTER-BLADDERS. 615 



granular cells which we formerly noted. There can hardly be any 

 doubt, then, that these embedded bodies are rightly regarded as 

 daughter-bladders. 



They gradually emerge of course from the deeper parts of the 

 cuticle, since new cuticular layers are always arising internally, as 

 those outside (p. 600) gradually disappear. The superjacent layer of 

 the cuticle of the mother-bladder becomes pushed forward as a sort of 

 hernia. The more the daughter-cell grows, the more accentuated does 

 the protrusion become, until it finally bursts and sets free its inmate. 

 In many cases the daughter-bladder becomes abortive soon after its 

 isolation (perhaps under the pressure of the surrounding wall of the 

 cyst), but in other cases it develops beside the mother-bladder. It is 

 at first enclosed in a lateral pouch of the original cyst, but in the 

 course of time it usually acquires an independent envelope, a partition 

 wall gradually growing up in the space intermediate between the 

 mother and daughter-bladder. In the last stage it is of course hardly 

 possible to distinguish the secondary JZchinococcus-loladdeYS arising by 

 proliferation from the primary parasite, which originated from the 

 metamorphosis of a six-hooked embryo. A valid difference, however, 

 seems to me to lie in the fact that the daughter-bladders are able to 

 produce brood-capsules sooner than their mothers. 1 



The objections which Naunyn urges against my observations have 

 to do less with the real facts for he himself admits having seen 

 peripheral daughter-bladders than with my assertion that they arise 

 " independently of the parenchymal layer of the mother." In this 

 expression I have, indeed, affirmed too much, more, in fact, than 

 I intended. At first I only wished to indicate that the daughter- 

 bladders have an independent development, and exhibit no permanent 

 connection with the parenchyma of the mother. As to the nature of 

 the granular mass which furnishes the point of origin of the daughter- 

 bladder, no additional light has been cast upon it by my observations, 

 but I have no scruple in deducing it from the parenchymal layer of 

 the mother. It obviously represents a portion of the latter, a bud-like 

 outgrowth, so to speak, which separates itself from the matrix, 2 and 

 becomes ever further separated from it by the subsequently formed 

 cuticular layers. In agreement with this is the fact that the daughter- 

 bladders, so long as they are small, lie in the deeper layers of the 

 cuticle, and only gradually work their way outwards. 



1 Morin observed the formation of heads (in a case of Echinococcus multllocularis) in 

 the daughter-bladders, although none of them had become separated (" Deux cas de tumeurs 

 a echinococquesmultiloc.," Dissert, inaug. Lausanne, p. 32, 1876). 



2 Naunyn sometimes saw (loc. cit., p. 631) a very fine canal running through the sub- 

 jacent layers of such a peripheral daughter-bladder, and even opening into the latter, so 

 that it looks as though this separation were sometimes delayed to a later period. 



