180 
THE CONDOR 
Vol. XVII 
There certainly is evidence of degeneracy of the eagle-like function of 
the foot. Let us examine the evidence. The points of attachment of muscles to 
bones are commonly marked by distinct roughnesses of very definite position. 
In a foot of great lifting power, the attachment of those muscles which bend 
the leg at the tarsal joint are relatively far down the shaft of the tarsus, thus 
affording greater leverage for the lift. In like manner one grasps farther 
down on the pitchfork handle in lifting a heavier shock of hay. Wading, run- 
ning, and walking forms of birds employ the opposite method of attachment, 
sacrificing lifting power to gain distance of stride in the foot. To continue the 
homely comparison, the hay-maker shifts his hand back toward the end of his 
fork-handle after the weight has been raised and he wishes to gain distance 
for heaving his hay upon the load. Morphnus 
daggetti has similarly shifted his grip on 
his tarsal lever, or he has accomplished what 
is in effect the same, by an extreme elonga- 
tion of the shaft beyond the point of muscle 
attachment. This great long-shanked eagle 
has a power arm in his lever no longer than 
that of the Ferruginous Roughleg ( Archibu - 
tco), although the resistance arm is almost 
twice as long as that of the same species. 
The Caracara (Polghorus ) , who walks as 
readily as a turkey, has almost exactly the 
same relative position of its muscle attach- 
ment as has this great extinct eagle. The 
conclusion is unavoidable that the lifting 
power of the foot was extremely low. 
But what of the grasping power of his 
toes? The three front toes of a bird are at- 
tached at the extremity of the tarsus to three 
articular surfaces known as trochleae. In 
the powerfully predaceous raptors these 
trochleae are deeply grooved and are set 
somewhat obliquely upon the shaft. Evi- 
dence of decline of the raptorial habit is 
seen in M. daggetti in the fact that these 
Morphnus daggetti (at left) trochleae are more uniform, less deeply 
and of Ardea herodias; both grooved, and are set less obliquely 
about two-thirds natural upon the tarsal shaft. This condition is 
carried to its extreme in the Old World 
vultures which are conceded to be degenerate raptors, and is in marked contrast 
to the conditions in Aquila and Haliaeetus. The conclusion seems inevitable 
that this peculiar asphalt species was of more or less ambulatory habits — a bird 
which had forsaken the more actively predaceous manner of his aquiline an- 
cestry and lengthened out his shanks in much the same way, though perhaps 
not to the same degree, as has the Roadrunner ( Geococcyx ) forsaken the tree- 
dwelling life of his cuckoo kindred to put on stilts. 
A condensed description of the new species is appended for the more tech- 
nical student. 
Morphnus daggetti, new species ; type specimen, no. A-380, Los Angeles 
Museum of History, Science, and Art ; a tarsometatarsus. Assignment of this 
