752 ON THE DEVELOPMENT OF BILHARZIA HjEMATOBIA. 
rian tube without impregnation (Fig. t). Another early form 
was perfectly spherical, with a well-marked chorional envelope 
and only a less marked double contour (Fig. r). These forms 
measured about -j'h/' in diameter. The fully grown eggs 
observed at the same time gave a longitudinal measurement 
of - 3 - 5-0 by T -oVo // in breadth. On adding any stimulus to the 
ova, such as diluted sulphuric acid, the embryos moved them¬ 
selves freely within the egg. After allowing the urine to 
stand for forty-eight hours, I found, on the 27 th of July, that 
the shells of the ripe ova had dissolved, leaving the embryos 
dead, but still coiled within a fine transparent envelope (Fig. 
v). In this state, they were easily separated and examined, 
when they gave a measurement of -^Fo" in length by - S " 5 ' So " in 
breadth. On two occasions, whilst engaged in rearing the 
larvae of Bilharzia in water, I noticed single specimens of 
these embryos lying dead; and one of the examples thus ob¬ 
served had evidently grown since it was extruded from the 
shell, for it gave a length of - x ~yq", by 3 - 0 V 0 " i° breadth. 
I have been thus particular in recording these facts, because 
future discoveries may enable us to identify the species of 
nematode to which these ova are referable. Putting aside the 
question of Spiroptera Jiominis (which the Berlin helmintholo¬ 
gist Schneider determined to be only the well-known Filaria 
piscium artificially introduced into the human bladder), I 
know only one set of observations on record which appear to 
refer to this same species of parasite. I allude to the state¬ 
ment of Dr. J. H. Salisbury, as given in Hay’s American 
Journal , vol. lv, for 1868, p. 376. In his paper on the 
Parasitic Forms developed in Parent Epithelial Cells of the 
Urinary and Genital Organs, Dr. Salisbury refers certain 
nematode ova to a distinct and new species of entozoon, 
which, although he has evidently never seen the parasite in 
the adult condition, he has had the boldness to conjecture, 
must belong to the genus Trichina. Of course there are no 
adequate helminthic grounds for this generic allocation; but 
the facts recorded by Dr. Salisbury do not on that account 
lose their remarkable interest and value. So important do I 
deem them in relation to certain vexed questions connected 
with urinary parasitism in man, that I do not hesitate to 
quote his brief description, which runs as follows: 
“ Trichina cystica (Salisbury).—This is a small species 
w 7 hich I have found in the human bladder. In all my exami¬ 
nations, I have met with this little entozoon in three cases 
only. In two of these it was only occasionally met with in 
the urine. In the other, a Mrs. R., of Cleveland, it occurred 
