239 
TRANSLATIONS. 
Notice of the OccurreNcr of a NEMATOID Parasite in the 
Ovum of Limax griseus. By M. A. Barruitemy. 
(From the ‘ Comptes rendus,’ Jan. 24th, 1859.) 
In studying the development of Limax griseus, I was not 
a little surprised to discover in the first ovum submitted to 
microscopic examination a minute Nematoid worm, in which 
might still be observed some vitelline granules. In other 
ova, more advanced in development, I have noticed similar 
vermicules, often to the number of three or four, and which 
had apparently undergone a development corresponding to 
that of the creature whose domicile they had invaded. At 
this stage they were large enough to be readily seen with a 
simple lens, performing tolerably active movements. In most 
cases they remain at some distance from the embryo, though 
occasionally I have noticed one of them attached to the 
vesicle which surmounts the head of the future mollusc. 
Lastly, in some ova still further advanced, the parasite had 
destroyed its host, the walls of the ovum were collapsed, and 
the Nematoid worms might be observed in the interior 
arrived at their full development—that is to say, furnished 
with the reproductive organs. 
The transparency of the worm renders a precise knowledge 
of its anatomical constitution easily attainable by simple 
microscopic examination. Its conformation appears to me to 
remove this worm so far from all known types, as to autho- 
rise the establishment for its reception of a new genus, for 
which I propose the name Ascaroides. The species I propose 
to term A. limacis. 
In the first place, I had to investigate the mode of origin 
of the worm. The presence of this animalcule within an 
ovum, to all appearance so efficiently protected against such 
Invasions, was an embarrassing fact. Having ascertained, 
by direct experiments, that the worm is present in the ovum 
at the time of oviposition, I subjected to anatomical inspec- 
tion under the microscope those slugs whose ova were thus 
infested. In several of these, I found in the alimentary canal 
and in the ovaries the parasitic vermicule still distended with 
vitelline granules, and always accompanied by a very minute 
monadiform Infusorium. I have seen and drawn two of 
these vermicules already installed in the ova in process of 
formation, and have thus discovered the complete vital cycle 
of the new parasite. 
