NOTES ON A GREGARINE OF THE EARTHWORM. 427 
nucleus the structure of this was peculiar, almost all the 
contents of the nuclear membrane being gathered into a single 
large mass, situated at one side (fig. 11). This is no doubt 
preparatory to division, which probably takes place with mitosis 
as described by Wolters in other Gregarines. The next 
stage which I have myself seen is one in which the nucleus 
has broken up into minute portions, of about the same size as 
the larger paraglycogen granules ; these fragments are scattered 
pretty evenly throughout the body of the animal, and are very 
inconspicuous. They were pointed out to me by Mr. Minchin, 
who kindly examined some of my preparations, and when 
once demonstrated were fairly easily seen, as in a preparation 
stained with hematoxylin and eosin they were dyed a distinctly 
bluer colour than the surrounding granules (fig. 12). I did 
not see any breach of continuity in the septum formed by the 
coalesced cuticles which separates the conjugating Gregarines, 
through which any interchange of substance might occur ; nor 
have I seen the nuclei or nuclear fragments apparently attracted 
towards one another in this species. In a specimen of Mono- 
cystis agilis, from one of the vesicule seminales of the 
worm, the nuclei of the two conjugating individuals were 
drawn together to the opposite sides of the septum (fig. 21), 
and probably the latter is ultimately entirely absorbed, as it 
does not appear in cysts containing spores. 
Sporoblastomeres and Sporoblasts.—The next stage 
is the formation of sporoblastomeres (Minchin) by the se- 
paration of the substance of the animal into masses, each 
surrounding a fragment of the nucleus. These appeared in 
fresh preparations to be surrounded by a transparent coat, but 
this is either not universally the case, or disappears in per- 
manent preparations (figs. 13 a, 6). In some the original 
granules still appear embedded; at a later stage these dis- 
appear, and the masses become homogeneous; they are of 
different sizes, and contain one or more nuclei (fig. 130). I 
have found specimens containing one, two, and four nuclei, sug- 
gesting a tetraschistic division into the ultimate sporoblasts. 
These latter become elongated and boat-shaped before secret- 
