ENTOZOA — GORDIACEA. 
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believes that the Mermis lives as a parasite in the larva of the May-bug, 
and that the latter, when the ground in which it lives is raoister than 
usual, is obliged to press its parasites out of its body, which also seek 
for an exit, in order to have an opportunity of depositing their eggs in 
the earth. He remarked, of a Mermis which he kept above eight days 
in water, that it desired to get out, and actually did escape, and laid its 
eggs on a dry place ; where also it was dried up, and did not again 
revive in water. Left to themselves, they probably spend a long while 
in water, when they feel no farther impulse to the laying of eggs. 
The Mermis is 100-125 mill, long, 0.5 to 0.6 mill, thick ; of a white 
colour, with a streak shining through from its interior, out of which the 
eggs develop themselves. The body tapers anteriorly, and behind the 
head is somewhat constricted ; the head itself is truncated anteriorly, and 
has an angular appearance, in consequence of several projecting papillae ; 
the tail-end is obtusely rounded. About fifteen mill, from the head is 
found a transverse cleft surrounded by padded margins, which represents 
the vulva, but it is neither connected with an uterus nor an egg-canal. The 
surface of the body seems quite smooth ; no anus could be found. With 
this account, the observations which the reporter had an opportunity of 
making on a worm of this species, found in water at Danzig, agree pretty 
closely. The cuticle of Mermis, according to Dujardin, consists of three 
dilFerent parts, — 1. A thin epidermis ; 2. A layer of fibres that cross each 
other obliquely, running spirally and uninterrupedly through the whole 
length of the body ; and, 3. A cartilage-like hollow cylinder, formed of 
from fifteen to thirty homogeneous and concentric layers. This car- 
tilaginous cylinder decreases in thickness in its passage forwards, while 
posteriorly the thickness increases. The reporter, in the Mermis 
examined by him, has not been able to discover this structure, but he 
found the cylinder to be composed of two muscular layers of compressed 
longitudinal fibres and distant transverse fibres. Dujardin mentions 
the muscular cylinder of longitudinal fibres as situated under the third 
cartilaginous cuticle. On the head, five or six very small papillae are 
observable, under which are found depressions, which are connected by 
small openings with the empty space surrounding the oesophagus. A 
broad band runs along the inner surface of the muscular cylinder, from 
which Dujardin supposes the eggs proceed. The reporter also observed 
these two bands, but cannot convince himself, that double rows of spots, 
of egg-germination, were present in them. The intestinal canal is simple, 
as from the simple mouth a narrow oesophagus passes into the dilated 
intestine, which is gradually lost posteriorly. The dusky stripe of the 
worm proceeds from the black-coloured eggs, which the reporter found 
enclosed in a narrow bag, but which, according to Dujardin’s account, 
should be in connection with the above mentioned problematic ovaries. 
The form of these eggs is very remarkable ; each consists of a colourless 
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