14 PASSERES. 
to each front toe. The Flevor longus hallucis arises from the 
outer condyle of the femur and from the intercondylar region. 
It accompanies, and is closely associated with, the /l. profundus 
throughout its whole length. Passing also isto the tendinous 
condition at the tyitieneel joint, it crosses the £7. profundus 
tendon near its middle, from behind and from without inwards 
to be inserted on the terminal phalanx of the hind toe. 
This, at least, is what obtains in all the Passeres save the 
Kurylemide, where the hallucis tendon anchors itself to the 
profundus tendon at the point where the two tendons cross, 
by a number of tendinous fibres, to form what is known as a 
“vinculum.” No less than eight different modes of anchorage 
between these two tendons are recognized. The typical Passeri- 
form type is No. VII. of this series; that of the Lurylemide is 
INo. I. , 
Nitzsch, in laying the foundations of the study of the pterylosis, 
opened up a field of great promise, which, so far, has only very 
partially been explored by systematists. The attempt to use the 
number of the remiges as a factor in the subdivision of the Passeres 
has only resulted in the formulation of a test which is based on 
error. Thus, in the previous edition of this work an attempt 
was made to form two Groups of Passeres, the one displaving 9, 
the other 10 primaries. This was unfortunate, since all the 
so-called ‘‘ 9-primaried” Passeres possess 10 remiges, while many 
of the so-called ‘ 10-primaried” Passeres possess 11 remiges. 
The error has arisen from a failure to distinguish vestigial quills 
and their coverts. In the ‘‘9-primaried ” Passeres the 10th may 
be reduced to the vanishing point. Where the 10th primary is 
conspicuously long, as in fhe Corvide, the 11th will be found as 
a ‘“remicle,” 1 cni. or more in length. Bearing these facts in 
mind, there can be no objection, for the sake of convenience, 
to the continued use of the division into 9-primaried and 10-pri- 
maried wings, the remicle being in both cases a negligible 
quantity. 
So tar, unfortunately, Ornithologists have made no more use of 
pterylosis than this numbering ot the wing and _tail-feathers. 
A vast ainount of work has yet to be done, in investigating 
the ptery losis of the trunk, for the sake of the evidence it will 
unquestionably furnish as to the relationship of forms whose 
affinities can at the present’ be no more than guessed at. The 
Parida, Aimpelide, Oriolide afford cases in point. True, we 
cannot discover this evidence by a study of the pterylosis alone— 
the osteology and myology of these puzzles must also be taken 
into account—but we shall have made ereat strides when this 
pteryological work has been thoroughly done. It is to be hoped 
that those who use these volumes will ‘endeavour to take up this 
much neglected work, 
The juvenile or “nestling” plumage of the Passeres Ae very 
valuable data to the systematist. In the last edition of this 
