393 
C. J. Sundevall on the Wings of Birds. 
the year 1835. Nevertheless I had not then grasped the 
whole importance of these characters as external distinctions 
between the birds which do or do not possess singing-muscles 
on the inferior larynx, for I still believed that I found excep¬ 
tions in the genera Picus, Upupa, and Menura. Later inves¬ 
tigations have shown that these genera do not deviate from the 
general rule, and that the presence or absence of the so-called 
singing-apparatus is indicated by two dissimilar structures of 
the wings. After the year 1834 other studies occupied my 
time, so that this subject did not again come under examination 
until the report of the statement of Keyserling and Blasius 
of the (in their opinion) first positive external characters for 
Song-birds, caused the subject to be again taken up in the 
zoological “Arsberattelse” of the Academy of Sciences, printed 
in 1841 (p. 126). As I soon afterwards, in the same year, 
undertook a journey into foreign countries, I communicated 
the matter to several individual zoologists, and also to the 
Meeting of Naturalists at Brunswick. The Transactions of 
that meeting, however, contain no more than had already 
been made known in print in 1835. A somewhat more 
detailed exposition of the subject was first made before 
the Meeting of Scandinavian Naturalists in Stockholm in 
1842, and this is printed in the Transactions of that 
Meeting (p. 685). In the present paper I venture to give 
a description of the bird’s wing somewhat more in detail. 
First Chapter. 
General Review. 
The bird’s wing consists of the following parts :—- 
1. The anterior extremity, namely :— Humerus (upper arm, 
PI. X. figs. 1, 2, &c., a ), cubitus (forearm, b), and hand 
(manus, c ), which again is composed of the carpus (wrist, v), 
metacarpus (middle hand, c), first phalange ( y ) and the 
second [z) } with the pollex (thumb, d). 
Although it is not my intention here to describe anything 
but the exterior and its coverings, it may nevertheless be 
stated in passing that the two bones of the forearm, the 
ulna (fig. 1 } g) and the radius (b), are always separate in birds. 
