66 
closely aggregated. (A portion of the same cyst more 
strongly magnified is seen in fig. 6.) The most external 
layer belonging to the parasite is a thick, faintly- 
staiming, structureless membrane, which I have denoted 
by (ect.). Next comes a thick zone (end.), more deeply- 
staming, of a finely granular nature, the greater part of 
which presents a most unusual appearance, and gives the 
organism its remarkable character. Centrally is what 
ean only be a nucleus (N), although of relatively huge 
size as in fig. 4, which is a section through another, 
larger, cyst, from underneath the skin. In each nucleus 
are several nucleoli (n), or rather karyosomes, since they 
retain the chromatic stain. Fig. 5 is part of the nucleus 
drawn under a high-power, and shews a faintly-staining, 
regular reticulum, which traverses a_finely-granular 
ground-substance, with karyosomes of all sizes, the larger 
being vacuolated and the smallest little more than 
granules. The nuclear-membrane is very thin and 
extremely irregular, and sometimes appears only as a 
boundary between the nucleus and the inner limit of the 
cortical region (shewn on the left im the fig. ). 
In fig. 6 [ have attempted to indicate the appearance 
of a portion of the cortex, as seen under a high power. It 
consists of a finely-granular matrix, staining with the 
plasma stain, in which are innumerable, usually separate, 
veticula or net work (vet.), in every variety of shape and 
size. These stain up deeply with chromatic stains, and, 
so far as I can make out, ave made up of threads of rodlets 
or granules, not easy to resolve. fach network is 
developed round a centre (which stains sometimes less, 
sometimes more, than the general ground-substance) ap- 
parently at its periphery. These structures do not com- 
mence quite at the external limit of the cortex and they 
cease some distance before its inner limit. On the whole, 
