NOTES ON A GREGARINE OF THE EARTHWORM. 429 
Position of Gregarines in the Worm.—A few more 
points remain to be noted. With regard to the position in the 
worm of the Gregarines at various stages, it may be mentioned 
that the adult gregarines and the cysts which I first found, 
also the conjugating pairs, lay in the ccelom of the worm, as 
before stated ; later on, in the summer, I had great difficulty 
in finding any in this position, but discovered that the cysts 
were to be found embedded in certain oval or sausage-shaped 
masses of tissue, which appeared to lie loose, or but slightly 
attached, beneath the gut in the hinder segments of the worm. 
These masses seemed to consist of altered and degenerated 
nephridia, and were in some cases composed entirely of cells, in 
others of an apparently structureless matrix, with a few cells 
here and there (fig. 18). The Gregarines occurred in them along 
with a number of encysted nematodes, so that it was impossible 
to say whether the growth in which they lay was due to the latter 
or to the gregarines; but Dr. Benham assured me that the 
formation was certainly abnormal in the worm.' If the Grega- 
rines were the cause of this growth, the fact might have a 
pathological interest, in view of the suggestion that some 
cancerous tumours are caused by a psorosperm, as is tlie case in 
the disease peculiar torabbits caused by Coccidium oviforme. 
The sausage-shaped growths in the worm were in some cases 
honeycombed with cysts of small size closely packed together 
(fig. 18) ; in other cases only a few larger cysts occurred in 
each. In one or two specimens of mature Gregarines, which I 
found apparently loose in the celom, there were a certain 
number of tissue-cells attached to the cuticle, showing either 
that it had once been embedded in a similar growth, or rather 
perhaps that it was about to embed itself, but interrupted 
before the process had proceeded far. The suggestion that the 
falciform bodies make their way out of the worm to find another 
1 Metchnikoff (6) records that the gregarine-cysts in the vesicule semi- 
nales become surrounded by a mass of phagocytes which attack and some- 
times succeed in killing them. The masses of cells above described seem 
also to be of an inflammatory nature, but it seems doubtful whether they 
injure the enclosed cyst, in which I have not noticed any marked signs of 
degeneration. 
