22 
as, for example, in the Cassowary, the Emeu, or the Ostrich, although 
the organization is essentially that of the Vertebrate animal modified 
for flight, flight is impossible ; and its immediate instruments, to the 
exercise of which all the rest of the system is more or less subordi- 
nated, are checked in their development ; and, being unfitted for 
flight, they are not modified for any other use. There is not, per- 
haps, a more anomalous or suggestive pheenomenon in nature than 
a bird which cannot fly! A small section of the Mammalia is modi- 
fied for flight ; but the plan of the organization of that warm-blooded 
class being less directly adapted for flight than that of birds, the 
weight and bulk of the body which may be raised and transported 
through the air are restricted to a lower range, and the largest frugi- 
vorous Bat (Pteropus) does not exceed the Raven in size. The Rep- 
tilian modification of the Vertebrate type would seem to be still less 
fitted for any special adjustment to aérial locomotion ; and in the pre- 
sent day we know of no species of the class that can sustain itself in 
the air which equals a Sparrow in size. And the species in question— 
the little Draco volans—sails rather than flies, upborne by its out- 
stretched costal parachute in its oblique leaps from bough to bough. 
Of the remarkable reptiles now extinct, which, like the Bats, had 
their anterior members modified for plying a broad membranous wing, 
no species had been discovered prior to 1840 which surpassed the 
largest of the Pteropi, or Flying-Foxes, in the spread of those wings, 
and there was, @ priori, a physiological improbability that the cold- 
blooded organization of a Reptile should by any secondary modifica- 
tion be made to effect more in the way of flight, or be able to raise a 
larger mass into the air, than could be done by the warm-blooded 
Mammal under an analogous special adaptation. When, therefore, 
the supposed bird’s bone (Geol. Trans. 1840, pl. 39. fig. 1) was first 
submitted to me by Dr. Buckland, which on the Pterodactyle hypo- 
thesis could not be the humerus, but must have been one of the 
smaller bones of the wing, its size seemed decisive against its reference 
to an animal of flight having a cold-blooded organization. The sub- 
sequent discovery of the portion of the skull of the Pterodactyle, de- 
scribed by Mr. Bowerbank at the last meeting of the Society (Jan. 
14), shows that the resources of Creative power in past time surpass 
the calculations that are founded upon actual nature. 
It is only the practised Comparative Anatomist that can fully realize 
the difficulty of the attempt to resolve a paleeontological problem from 
such data as the two fragments of long bones first submitted to me in 
1840. He alone can adequately appreciate the amount of research 
involved in such a generalization as that “there is no bird now known, 
north of the equator, with which the fossils can be compared ;”” and 
when, after a wearying progress through an extensive class, the spe- 
cies is at length found to which the nearest resemblance is made by 
the fragmentary fossil, and the differences are conscientiously pointed 
out—as when, in reference to the humerus of the Albatros, I stated 
that ‘it differs therefrom in the more marked angles which bound 
the three sides’’—the genuine worker and searcher after truth may 
conceive the feelings with which I find myself misrepresented as 
