20 W. P. PYCRAFT. 
ungual phalanx, while Digit IIL. is slightly shortened and terminates in a point. The 
humerus in the adult, like the rest of the wing, has undergone great flattening, as well 
as marked changes in its extremities. Its distal end has become twisted on itself, so 
that the radial and ulnar condyles lie one above the other, instead of side by side, and, 
further, have become reduced so as to form confluent facets, while the olecranon process 
is now produced backwards into a prominent, triangular spur, bearing two deep 
grooves for the lodgment of sesamoids of large size. The proximal end has also under- 
gone considerable changes, the most marked of which are the increased size of the 
glenoid surface of the head and the great size of the fossa trochanterica. The skeleton 
of this limb is non-pneumatic. The result of these modifications has been to permit 
the several segments of the wing to be extended so as to form a straight-jointed rod, 
but one allowing of but little motion between the joints. In the normal wing the hand 
can be straightened out upon 
the forearm, but the latter is 
always, from the nature of its 
articulations, bent upon the 
humerus. But then, of course, in 
the one case the wing is used as 
a paddle, in the other for the 
purposes of flight, though the 
paddle of to-day, there can be no 
doubt,was earlier used as a wing. 
The Tarsal and Metatarsal 
Bones. 
FIG. 6.—THE DUODENAL LOOP OF A NESTLING EMPEROR PENGUIN. In the embryo of the 
Emperor Penguin, to which the 
wing just described belonged, the tarsus is wholly cartilaginous, but the proximal row, 
though showing no separate elements, is yet free and is applied in the form of a 
cartilaginous pad to the bones of the metatarsals I-IV. The metatarsals are also all 
free, and, it is important to remark, have the form of perfectly cylindrical shafts, thus 
showing that the peculiarly broad and semi-distinct metatarsals of the adult have not 
assumed this shape by a secondary flattening process, as some have suggested, but 
that the tarso-metatarsus, on the contrary, actually presents a primitive stage. 
VIUl—tTae Inrestinat Tract. 
Dr. P. Coatmers MitcHey (12) has described and figured the intestinal tract of 
Catarrhactes, Spheniscus demersus, and Aptenodytes patagonica, his preparations being 
made from adult specimens. I am enabled here to add descriptions of this tract in the 
Emperor Penguin, A. forsteri, and the Adélie Penguin, Pygoscelis adeliz, but unfortu- 
