82 Mr. Fohn Flower. 
Ig.—ON THE PECULIAR SHAPE OF THE CLAW OF THE 
MippLE Tor oF Birps. 
By the President. 
[Read December 15th, 1880.] 
The peculiarly serrated shape of the claw of the middle toe 
of the Nightjar (C. Europceus) is well known, and many are 
the ingenious theories which have been framed to account for 
its peculiar form. The claw of the middle toe is also serrated 
in the Herons and Cormorants, and in other birds peculiarities 
in this claw have been noticed. It is not, however, my inten- 
tion now to go through these in detail, or to endeavour to 
explain the reason for their peculiarities. I propose on the 
present occasion merely to point out a matter of some interest, 
which seems to throw some light upon the peculiarities to 
which I have referred. 
The number of birds in which peculiarities in the claw of 
the middle toe have been noticed and described is compara- 
tively small, and it is somewhat singular that all naturalists 
who have dealt with this subject have described these cases 
as something altogether exceptional, as if, in fact, they were 
the only birds in which this claw is different from the others. 
I believe, however, that a close and exhaustive examination of 
the feet of birds would show that there are very few, if any, 
birds in which the claw of the middle toe is not more or less 
modified in form. The outside edge of this claw, as a rule, is 
not peculiar, but the inside edge is so far modified that it is 
easy to tell whether any particular foot is a right foot or a left 
foot by this peculiarity alone. 
The series of birds’ feet which I have here, and which 
comprise nurnerous examples from each of the five orders into 
which British birds are divided, will make this very clear. In 
all of them the inside edge of the middle claw is much developed 
and altered in shape. 
It would be dangerous to attempt to frame a theory to 
account for this peculiarity until the matter has been more 
fully considered and investigated, but I hope our members will 
not lose sight of this subject, and if any remarkable modifica- 
tion of this claw should come under their observation they 
should not fail to bring it forward at one of our meetings. 
