ON THE NEMATODES OF THE COMMON EAHTHWOEM. 609 
carried on. I have also been assisted by a grant which was 
made me at the commencement of the work from the Endow- 
ment of Research Fund of the Birmingham Natural History 
and Philosophical Society. 
Occurrence. 
(1) The Encysted Larva inhabiting the Coelom. 
The encystedform is most plentiful in the posterior end of the 
coelom. In dissecting Lumb. terrestrisa number of flat- 
tened and roughly oval bodies of brown matter varying in 
length from 1 to 5 mm. are to be found lying round the intes- 
tine close to the anus, in the compartments formed by the 
septa. These brown bodies, when placed in water and exa- 
mined iinder the microscope, are at first too solid and opaque 
to show of what they consist. But in some instances a few 
nematodes are to be seen partly imbedded in them and partly 
free, their free ends waving about in the water. Occasion- 
ally large, white, rounded bodies are present, projecting from 
the surface. These are cysts of Monocy stis. 
When one of the brown bodies is placed in water a number of 
unencysted larval nematodes make their escape from it before 
very long. In the course of one or two days it gradually 
disintegrates. It is then seen to be constituted of numerous 
small, and occasional large, cysts of species of Mono- 
cy stis, discarded setae of the worm (sometimes still encased 
in the setigerous sac), encysted nematodes (of which some 
have already escaped from their cysts and others are in the 
act of doing so), and lastly a large quantity of loose brown 
cellular matter, which consists of broken-down, discoloured 
amoebocytes, and has held the whole mass firmly cemented 
together. Lankester (5, p. 104), de Ribaucourt (11) and 
K. C. Schneider (13, p. 425) have all described these inclusions 
of the coelomic fluid at the posterior end of the body, and my 
observations agree with theirs. 
The cyst enclosing the nematode fits round its body closely. 
