McIntosh, on the Gregariniform Parasite of Bor lasia. 41 
These ova are altogether different from the ova of the 
Borlasia itself, which have large capsules, each with a neck 
ending in a long slender microscopic thread, the contents 
undeveloped, and otherwise totally dissimilar, and deposited 
in a large mass of consistent gelatinous substance, as first de- 
scribed by E. Desor.* It is curious, however, that the para- 
sitic ova should be provided with a similar coating when 
extruded under pressure, and this coating is seen connecting 
the ova within the body of the worm towards its posterior 
end. The appearance of the contained embryo is much in 
favour of its identity with the gregariniform bodies, though 
as y£t I have not seen a perfect bond fide birth. These ova, 
too, occurred in greatest plenty in August, whereas both 
Desor and I have found the ova of the Borlasia deposited 
towards the end of January. Kolliker does not specially 
mention the ova of his G. Nemertis. Max Schultze mentions 
and figures what he calls entire spheroidal forms, which 
differ from the ova above mentioned in being simple cells 
without thickened coats, and may or may not be in relation 
to the gregariniform bodies. 
The small bodies shown in fig. 4 were extruded with the 
parasitic gregarinse in great numbers ; they were generally of 
an ovoid or pyriform shape, a few being circular, and con- 
tained many clear granules. The diameter of these structures 
was about T o L (nj th of an inch, or rather more, whereas a speci- 
men of a stray gregariniform parasite from the same annelid 
measured -p^th of an inch ; therefore they do not seem to be 
cysts formed after the conjunction of two gregarina?. 
Occasionally one of the parasites is observed in a degene- 
rating condition, forming an ovoid body in which the bent and 
atrophied gregarina is scarcely distinguishable. 
The large number of these gregariniform bodies, in some 
examples of the Borlasia 5 , must give them a position of im- 
portance — whether beneficial or prejudicial — in the economy 
of the annelids. 
# ‘Miiller’s Arckiv 5 for 1848, p. 511, pi. xviii, &c. I have not yet seen 
the American version. 
