322 PROFESSOR OWEN ON THE SKELETON 
The first free caudal has a depressed subquadrate centrum, broad and depressed 
diapophyses inclined backward, with terminal pelvic articulations as above stated. 
The second, third, and fourth caudals diminish in size, and more so in the breadth of 
the diapophyses, which end freely. 
A small hemapophysial tubercle is wedged between the second and third caudal 
centrums ; a larger plate is between the third and fourth caudals ; it begins to be com- 
pressed between the fourth and fifth caudals. The next hemapophysis resembles a 
short compressed spine, inclined forward; the fifth and sixth hemapophyses diminish 
in size; the seventh and eighth are elongate bones underlying the centrums, with which 
they are nearly coextensive. One sees that the under and fore part of the terminal 
anchylosed mass of caudals is a confluent hemapophysis of like shape. 
The diapophyses increase in length from the fourth to the seventh caudals’; these 
decrease in the eighth and ninth, and disappear in the tenth. The neural spines are 
stumpy and thick on the anterior caudals, look longer, because thinner, on the succeeding 
ones to the ninth, are short on the tenth and eleventh, and are represented by a con- 
tinuous ridge on the terminal coalesced vertebre. The length of the caudal region is 
3 inches 9 lines. 
From the position of the acetabula, and prior to sacral confluence, there would be 
shown eighteen free caudal vertebre in the young Garfowl: one sees that if these 
vertebra had continued free and participated in the rate of growth of the antecedent 
centrums, how similar a caudal appendage to that of the Archeopteryx' would have 
resulted. 
The sternum (PI. LI. hs, 60; Pl. LIT. figs. 1 & 2) is long, narrow, entire, with the 
keél (As) equalling in depth the breadth of the mid part of the bone. The epister- 
num (e) is short, compressed, wedge-shaped, with its thin obtuse apex curved a little 
down and back. The ‘‘ coracoid”’ grooves (6) are separated from each other by the 
base of the episternum (e): each is divided into an inner and an outer articular facet ; 
the inner one (PI. LII. fig. 2, b) is the largest, and is subtriangular, the broadest part 
being sustained by a kind of buttress-like prominence, each buttress (f, f) diverging 
from the fore part of the origin of the sternal keel (hs). The outer facet (ib. 6’) is 
bounded by a short plate in front, and by the base of the costal process behind. 
The “costal” process? (d) is subcompressed, triangular, with an obtuse apex directed 
1 Phil. Trans. 1863, p. 44, pl. 1. 
* See the definition of this and the other processes in art. A4ves, ‘ Cyclopzedia of Anatomy and Physiology,’ 
vol. i. 8vo, 1836. The sternum of the bird is not the homologue of the plastron of the Tortoise; it is never 
developed from longitudinally consecutive series of lateral elements such as represent the heemapophyses of 
certain dorsal segments in Chelonia. In most birds ossification of the sternum begins from a pair of centres, 
which, meeting and coalescing at the mid line, thence extend into the cartilaginous basis of the keel. The extra 
pair in the anomalous sternum of Gallinz is special and exceptional in the Bird class. The application of the 
names of the elements of the Chelonian plastron to parts of the Avian sternum is to be deprecated, save in the 
case of the episternum, the bifurcate character of which is shown by bone in Passerines. 
