770 The American Naturalist. [September, 
when westudy not only my figures 1 and 2, but the figures of 
Rosenberg and Zehntner. In the figures just cited the tem- 
porary digit is just as prominent as is the “pollex” and no 
one without a theory to support would regard it other than a 
digit. Then too, as Rosenberg’s figure shows, it bears no con- 
nection to the ulnare, but isa distinct outgrowth from the 
outer distal angle of carpal III--IV. 
We are then left to choose between the formule I, II and III 
and II, III, IV, and though the apparent weight of authority 
is in the other direction, I am strongly inclined towards the 
second alternative, for the following reasons: First comes the 
law of digital reduction advocated by Morse, by which in 
other groups digit I is first to disappear and then V. Fur- 
ther, when further reduction occurs in birds, and a single digit 
is left as in the Apteryx and the Cassowaries, the reduction has 
oceurred on both sides of the persisting digit, which, according 
to my nomenclature, would be digit III. This implies a sym- 
metrical reduction, the other view involves the disappearance 
of digits I, III, IV and-V, a condition, so far as Iam aware, 
without parallel. : 
Then too, Archaeopteryx, in the light of Hurst’s later 
studies presents some evidence. As noted above, Owen 
thought he had found evidence of a true digit I in the British 
Museum specimen, but on the discovery of the Berlin speci- 
men this idea was dropped and the conditions presented by 
the new example form the chief argument in Jeffries’ summary 
already alluded to. It would, however, appear that most recent 
figures of the Berlin specimen and the conclusions based upon 
them are not to be relied upon. This can be at once seen by 
comparing for instance the figure of Archaeopteryx given by 
Zittel in his Paleontologie with the photographic reproduction 
which illustrates Hurst’s article? In the Berlin specimen 
three digits in the wing are clearly visible, and it has been 
assumed that these were the only ones. Hurst, however, 
points out that the position of the feathers is such that they 
could not have been borne on these digits as in ordinary birds, 
"The plate in the Standard Natural i ( Vol. IV, facing p. 22, — ap- 
proaches very closely the figure of Hurs 
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