a doubtful amphibious Animal of Germany. 255 
which seem to anastomose with the branches of a smaller 
vessel, probably an artery, running on the opposite side. The 
other branch goes, in the manner before described, to the 
ovary of the left side, which is likewise connected by a mem- 
brane with the mesentery. 
Upon opening the pneumatic bag above mentioned, I found it 
quite simple, without any cellular structure, as in other amphi- 
bious animals ; but there was an intermediate membrane, which 
separated it into two cavities, between which, however, a com- 
munication was left, at the upper end of the bag, by a large 
semilunar opening. The communication of these cavities, with 
their respective ducts and bladders, was plainly shewn by 
blowing air into them, which readily passed from one to the 
other : indeed the ducts, though very narrow, admitted water 
to be driven through them by means of a fine syringe, so that 
I was able to fill both bladders entirely. In the back of the 
upper part of the bag there is a small opening, which ter- 
minates, by a very narrow canal or trachea, in a small slit or 
glottis, at the bottom of the lower jaw; shewing very evidently, 
that these parts constitute the respiratory organs or lungs of 
this animal. 
I shall not attempt to construct any hypothesis respect- 
ing the nature and manner of living of this animal, or make 
any deductions respecting the singular structure of these 
parts, so much deviating from the common organization. I 
shall only remark, that Mr. Schneider, in his work already 
quoted, mentions, though obscurely, and only in a few words, 
(p. 63, &c. ) that he observed a similar structure of the respira- 
tory organs, in what he supposes a larva of the Lacerta palus- 
tris. It seems extraordinary that he paid so little attention to 
