GREATER FLYING FISH. 
133 
particularly at their union with the body, is exceedingly inter- 
esting, as might be supposed from the use to which they are 
applied. Owen remarks that the bone equivalent to the radius 
in higher animals is of enormous size; but the description is 
given more at length in a paper on E. volitans, by Thomas 
Brown, in the sixty-eighth volume of the ^‘Transactions of the 
Royal Society,” (Part the Second for the year 1778.) He says, 
the united ends (of the rays of the pectoral fin) are grooved 
or hollowed, to receive a ridge or protuberance of the scapula, 
(or blade bone,) forming a joint of little motion except backward 
and forward, allowing the fin in one case to lie close to the 
side, and in the other to form an acute or right angle with 
the body, but without being necessarily expanded; (and thus 
the size of the fin is not a hindrance in rapid swimming.) 
From near the backbone downward to the bottom, where it 
ends in a point behind the gills, the body is strengthened on 
each side with a flat bone; both firmly united together at the 
place where narrowest, but as they become wider upward they 
grow hollow on the side next the body; and towards the gills 
the edge on each side is turned outward, so as to form a lodg- 
ment for a strong muscle; and on the hindward part is the 
articulation with the fin. Close above the joint, the bone he 
terms the scapula is hollowed in the shape of a crescent, in 
order to allow the passage of a tendon from a small muscle 
which lies in its lower part next to the body of the fish. The 
upper part of the ridge which forms the joint, and is received 
by or articulated with a fin, is somewhat enlarged and round- 
and over it the strong tendon, which is bound down by a lio-a- 
ment, together with some fibres of the muscle lodged under the 
inverted edge of the bone, is obliged to pass; and then passing 
over the joint, becomes inserted into the root of the uppermost 
and strongest fin-ray; and near the same place, a little way 
beyond the joint, is also inverted the tendon which passes along 
the semilunated part before mentioned of the scapula as over 
a pulley. These two muscles have their action upw'ard, but 
in opposite directions; and thus the fin becomes expanded and 
raised; while the lower portion of it is kept down by an 
opposing influence on the hindmost and lower muscles of the 
body. There are other muscles also of smaller size which 
cause this fin to move backward and forward; and the whole 
