Encystment of Aolosoma. 15 
Enchytreus given by d’Udekem (on p. 9 of separate copy of 
his memoir already quoted) the two processes at either end of 
the cocoon are extremely rudimentary. In another memoir * 
published about this same time, dealing principally with the 
embryology of Lumbricus, a figure is also given of the cocoon 
of Enchytreus galba—it is evidently from the same drawing 
as that which furnished the figure already referred to. The 
cocoon and contents are thus (on p. 49) described :— I] n’y 
en a jamais qu’un seul [ceuf] dans une capsule; celle-ci est 
sensiblement sphérique et enveloppe complétement l’ceuf ; 
seulement il y a deux points opposés ot on rencontre une 
légére protubérance.” 
With these illustrations and descriptions before him one 
could not be blamed for regarding the structures figured by 
‘ Maggi as cocoons, from the drawings of which the “ protu- 
berances ” had been omitted, since their slight development 
rendered them inconspicuous, and therefore easily passed over, 
The only difficulty in the way of making this comparison 
would be the increase of size in the cocoon—a fact not readily 
intelligible on the hypothesis of its being a cocoon. 
In every drop of water which I examined from the source 
already mentioned there were not only specimens of olo- 
soma Khrenbergit crawling about, but very numerous round 
capsules, containing what looked at first like developing 
embryos of M{olosoma. 
These capsules seemed to be occasionally attached to frag- 
ments of weeds Kc. ; but I fancy that they were merely lying 
upon these bodies, and had no real connexion with them. In 
any case there was no observable means of attachment, and 
they were as commonly found lying freely in the water at 
the bottom of the vessel in which they were placed. 
Each capsule contained a single olosoma, which appeared 
to be always bent once upon itself, the tail lying close to 
the head. The capsules were nearly invariably perfectly 
spherical, but sometimes more irregular in form or oval ; 
otherwise they recall Maggi’s figure (fig. 11, F), where the 
“‘embryo ” is represented as being coiled in a position very 
similar to that which I found. These capsules are quite 
visible to the naked eye, their average size being about that 
of Volvox globator. 'Vhey are in every case perfectly motion- 
less—that is to say, there was no motion of translation ; the 
worms inside were, however, in active movement — not 
crawling about within the cysts, but showing active contrac- 
tions of the body and movement of the alimentary canal, the 
* “Développement du Lombric terrestre,” Mém. cour. et Mém. d. say., 
etc., Acad. Roy. Belg. t. xxvii. 
