368 
PROFESSOR OWEN ON THE MEGATHERIUM. 
remained one condition, — viz. the power to employ a competent artist to depict the 
skeleton and its several parts. There could be no question that the opportunity of 
supplying the omissions, correcting the errors, and clearing up the doubts, in the 
descriptions founded on the Madrid skeleton, ought to be embraced without loss of 
time. The enlightened and liberal grant of £1000, placed by Lord John Russell, 
then Prime Minister, at the disposal of the Council of the Royal Society, in aid of the 
labours of men of science, seemed to me to afford the means of removing the only 
difficulty that stood in the w'ay of completing the object of my wishes. I therefore 
submitted the case to the “Committee of Recommendations for the application of 
the Government Grant,” and the Council of the Royal Society has been pleased to 
approve the recommendation of the Committee, viz. “that £100 be granted to Pro- 
fessor Owen, to be applied to the procurement of drawings of the undescribed and 
unfigured or inaccurately figured parts of the skeleton of the Megatherium, on 
the understanding that Professor Owen undertakes to select the subjects, direct 
the artists, and communicate his descriptions to the Royal Society; and that 
Mr. Darwin, Mr. Bell, and Dr. Sharpey, be a Committee to ascertain the proper 
application of the funds.” 
The memoir, and its illustrations from the accurate pencil of Mr, Joseph Dinkel, 
herewith communicated to the Society, are the result of that recommendation ; and I 
have only to add, that the descriptions and figures of the several parts of the skeleton 
of the Megatherium, novr in London, have been taken from the actual bones ; and the 
views of the entire skeleton from the articulated casts, which are so beautifully exact, 
as, for all the essential purposes of science, to be of the same value and utility as 
the bones themselves would be if so articulated together. 
Of the Spinal Column. 
The skeleton of the Megatherium, like that of all other vertebrate animals, being 
composed of a series of segments, similar in their composition, and referable under 
all their modifications to a common type, answering to that which is figured as the 
‘ typical vertebra’ in my work on the Vertebrate Skeleton*, I shall commence its 
description by one of those segments which deviate least from the archetypal cha- 
racter ; and such segments we find to constitute the major part of the trunk, where 
they form what, in human anatomy, would be termed ‘dorsal vertebrae,’ ‘ribs,’ ‘car- 
tilages of ribs’ and ‘sternal bones.’ 
Plate XVI n. fig. 1, gives a front viev/ of the fifth segment of the dorsal or thoracic 
region of the tnudv ; it deviates from the archetype inasmuch as the neurapophyses, 
have coalesced, as in other mammals, with the centrum, c, below, and are connate 
with the neural spine, ns, above: the haemal arch is also vastly expanded in relation 
to the greatly developed vascular centres which it was destined to encompass ; the 
* On the Archetype and Homologies of the Vertebrate Skeleton, 8vo, 1848, p. 81, fig. 16, and p. 82, 
fig. 15. 
