Prof. Reinhardt on Emballonura canina. 387 
wing being spread, it has the form of a longitudinal fissure, 2 
lines long, which extends immediately to the free outer edge of 
the membrane, is provided with thick lip-formed edges, and leads 
into a small cavity stretching itself along the margin of the alar 
membrane inwards to the body, becoming more and more narrow, 
and ending at length about 12 line from the fissure. The wing 
being extended, the two lips of the aperture glide from each 
other, so that the cavity opens; but when the wing is at rest or 
only half-extended, the innermost, that is to say, that lip which is 
nearest to the body, glides over the outer lip and thus covers it. 
Besides this, the small bag is provided with particular muscles, 
on the contraction of which it must open; for im the alar mem- 
brane are seen fine muscular fibres, which run from the edges of 
the aperture in a parallel direction with the outer edge of the 
alar membrane, partly towards the body, partly towards the 
thumb. The interior surface of the bag is without folds or 
wrinkles. 
On comparing the descriptions of the corresponding organ of 
Saccopteryax with the above-described glandular apparatus of the 
Emballonura canina, several material differences may be disco- 
vered: first, the bag of the Saccopteryx is somewhat differently 
situated, viz. just at the bending of the joint of the elbow, while 
in the Emballonura canina, as has already been mentioned, it is 
placed near the edge of the wing; further, the interior surface of 
the bag in the former is provided with several sharp folds or 
wrinkles immediately within the opening, which I have not found 
on the latter ; finally, the bag of the Saccopteryx is much larger, 
and has the appearance of a sharply limited protuberance on the 
lower side of the wing, while in the Hmballonura canina it is but 
slightly perceptible. 
The males only of the Emballonura canina possess the above- 
described organ; in the females the bag-like cavity is totally 
wanting, but the lip-formed edges of the fissure exist in a rudi- 
mentary condition, being represented by two very fine and sharply 
limited folds of the skin, of which the largest (which corresponds 
to the inner lip) scarcely rises the eighth part of a line*.. This 
glandular apparatus is no doubt one of the means by which the 
sexes are enabled to recognise each other; and it appears to me 
very probable, that in the Saccopieryx likewise, the bag will 
prove to be a sexual character, a supposition which may find some 
confirmation in the fact of the specimen described by Dr. Krauss 
being a male, and the same, if I am not mistaken, being the case 
with a specimen in the British Museum, which Mr. Gray kindly 
* This rudimental state is, no doubt, the reason why it has not been ob- 
served by the Prince of Neu-Wied, who founded his description of this bat 
upon a single female specimen. 
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