Jeffries on the Primaries of Birds. l6l 
ten coverts. The same number is found in the young, though the 
first covert is very small. 
Anisodactylce. I have not been able to examine any young 
of this group, which it is especially desirable to do, since in the 
Kingfishers the t adult has ten primaries, ten coverts, and a “ little 
feather,” which may be another primary. This at least is the 
case in Ceryle alcyon and in species of Dacelo. 
Pici. In Picoides arcticus the young gives the following 
formula: Pr., io, pr. c., 9, 3rd row, 6. In the nestlings of this 
species and of Colaptes auratus , the only young Woodpeckers 
I have seen, the last three or four primaries are very small and 
seem not to become fully grown till after the moult. This may 
be an adaptation to the home of the young bird, since it enables 
the wing to fold up close with less pressure on the growing 
feathers than would be the case if they were all fully developed. 
Accifitres. Among the Plawks, I have examined the young 
of Buteo Pennsylvania's and found, to my surprise, eleven prima- 
ries, ten coverts, and a terminal claw. That it was a true claw 
there can be no doubt, its resemblance to the undoubted claw of 
the I finger or thumb being complete. The presence of the claw 
is here of interest, as it points to the existence of a third phalanx, 
a thing not accredited to the Hawks and not ossified in my skele- 
ton of the Sharp-shinned Hawk (Accifiiter fuscus ) . I limit my 
remarks to this specimen, since, judging from the almost univer- 
sal absence of the ungual phalanx of the thumb, no reliance can 
be placed on museum specimens. In adult Buteones there is a 
small feather in the proper position for the first primary, but 
structurally it is only a contour feather. This may be developed 
from the first primary papilla or the papilla may abort; it is 
difficult to say which. 
Of the remaining groups of birds my observations have been 
even more sparse than in the foregoing. For convenience I will 
next consider the Ducks, taking a domestic Duck in illustration. 
In this case, as is true of all the lower birds, down tufts are 
developed from the papilla? of the primaries, thus making a 
strong contrast to the young birds previously described, where 
the papillae assume the structure of pin-feathers before they burst. 
So instead of simply counting the papillae we must separate out 
the little tufts and count their number. If this is done in the 
case of a young Duck eleven primary tufts and ten smaller covert 
