IN THE VENTRICLES OE THE VERTEBRATE HEART. 
495 
Fig. 40. Right and left ventricles of the turkey’s heart, opened anteriorly. Shows the 
somewhat triangular shape of the muscular valve ( i ) of the right ventricle of 
the bird, with its spindle-shaped muscular band (A), as contrasted with the 
anterior and inner segment of the bicuspid valve ( v ) of the left ventricle, 
with its chordae tendineae and musculus papillaris (y). The spindle-shaped 
muscular band is to the muscular valve of the right ventricle of the bird 
what the anterior musculus papillaris and its chordae tendineae are to the ante- 
rior segment of the bicuspid valve of the left ventricle. See pages 470, 471, 
& 472. 
Fig. 41. Transverse section of the ventricles of the heart of the emu, half an inch from 
the base, seen from below. Shows the shape of the right and left ventricular 
cavities, and the appearance presented by the muscular valve (gi) when viewed 
from beneath. See pages 470, 471, & 472. 
Fig. 42. The heart of the dugong, seen anteriorly. Shows the peculiar plaited arrange- 
ment of the fibres of the ventricles, and the bifid or double apex. See page 448. 
a. Aorta. 
k. Pulmonary artery opened into, so as to expose the sigmoid or semilunar 
valves. 
c. Left auricle opened into. 
d d'. Plicated arrangement of the external fibres. 
z. Plicated arrangement of the internal fibres. 
i. Segment of the tricuspid valve. 
p. Anterior musculus papillaris of the right ventricle. 
y. Portion of the left ventricular wall and posterior musculus papillaris with 
chordae tendineae. 
m. Right apex. 
n. Left apex. 
Fig. 43. Right and left ventricles of the heifer’s heart, seen posteriorly, the right 
ventricle being opened into, to show the arrangement of the carneae columnae, 
musculi papillares, & c. See pages 469 & 470. 
Fig. 44. Right and left ventricles of the human heart, seen posteriorly, the right ventri- 
cular wall being opened into, to show the distribution of the carneae columnae 
and musculi papillares. Shows the comparatively reticulated structure of 
the carneae columnae and the bifid nature of the musculi papillares, See. See 
page 470. 
PLATE XV. 
Fig. 45. Right and left ventricles of the sheep’s heart split up or separated from each 
other anteriorly. Shows how the fibres of the right and left ventricles are con- 
tinuous with fibres having a similar direction on the septum. See page 466. 
k. External fibres of the right ventricle becoming continuous, in the track for 
3 u 2 
