s 
196 General Notes, [ Feb. 
the large end of the blastocyst. (Fig. 2.) A sinuous vessel, re- 
vealing the existence of a water vascular system, could be plainly 
uniting in the median line at the smaller end. At the larger end 
they seem to be merged in the common parenchyma. In the 
immediate vicinity of the embryo the blastocyst is more trans- 
parent than in other parts, and the embryo seems to be held in 
position by a limiting membrane which lines the blastocyst and 
surrounds the embryo. When considerable pressure is applied 
the embryo is forced through the walls of the larger end of the 
blastocyst. The parenchyma is then seen to be confined to the 
thick walls of the blastocyst, as it does not flow out when the 
walls are ruptured. I succeeded in separating the wall of the 
blastocyst into two distinct coats, the outer one much thicker 
an the inner. In the outer coat three distinct layers were dis- 
tinguishable ; an outer granular layer, under which was a layer 
of longitudinal muscular fibres, and under this a thick layer in 
which were the characteristic refractile masses. These layers 
were not separable from each other. The thin inner coat, which 
tained a few irregular, flat, granular masses. The presence of 
transverse muscular fibres was not demonstrated, although their 
existence was shown by the power which the blastocyst had to 
contract and expand lawerally. They probably lie in the outer 
granular layer. 
The irritability and contractility of the blastocyst continue for 
several hours after the embryo is removed. In earlier stages of 
the development of similar forms, before the embryo is‘ c learly 
outlined within the blastocyst, the individuality of the latter is 
even more clearly marked, and is strongly suggestive of the 
from a’six-hooked larva, as in most other Cestoidea, and whic 
er the manner of a nurse, gives rise to an embryo by internal 
gemmiation, This embryo, when ready to escape from the blas- 
tocyst, is a scolex similar in form to the adult, and if transferred 
to a proper host would develop directly into an adult strobile. 
The embryo, when freed from the endocyst (Figs. 3, 3 4, and 
4), Was quite active, and consequently definitely accurate meas- 
urements of many of the dimensions were impossible. Its length i 
was about 24 mm., although it was capable of varying this to a 
considerable degree both by contraction and extension. 
ae are ant in number, marginal, oblong, widely divergent 
behind, a each other, but not uniting, in front; notche 
on the posterior Badd and obscurely two-lobed; edges free, 
o thin, and mobile. Length of bothria, Seance while paewhat 
_ flattened under the compressor, 2.23 mm.; breadth of head, com- 
” 
