14 PASSERES. 



to each front toe. The Flexor longus huUucis arises from the 

 outer condyle of the femur and from the intercondylar region. 

 It accompanies, and is closely associated with, the Fl. profundus 

 throughout its whole length. Passing also into the tendinous 

 condition at the intertarsal joint, it crosses the Fl. profundus 

 tendon near its middle, from behind and from without inwards 

 to he inserted on the lerminal phalanx of the hind toe. 

 THIS, at least, is what ohtains in all the Passeres save the 

 EurylcemidcK, 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 recogni/.ed. The typical Passeri- 

 forin type is No. VII. of this series ; that of the Eun/lcemidce is 

 No. I. 



Nitzsch, in laving 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 

 lias only resulted in the formulation of a lest 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 displaying 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-pi-imaried " 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 the Corvidse, the llth will be found as 

 a " remicle," 1 cm. 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 far, unfortunately, Ornithologists have made no more use of 

 pterylosis than this numbering ot the wing and tail-feathers. 

 A vast amount of work has yet to be done, in investigating 

 the pterylosis 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 

 Paridce, Arnpelidce, Oriolidce 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 great 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 affords very 

 valuable data to the systematist. In the last edition of this 



