of certain Fishes of the Ganges. 47 



the function of the glottis, and thus produce a slight hissing 

 noise, as may occasionally be heard, when the air is forcibly 

 expelled from the bladder. The heart is situate upon the in- 

 ferior surface of the oesophagus, close to its termination at the 

 stomach : and from the extreme proportional length of that 

 tube, is at a much greater distance from the organs of respira- 

 tion than is the case in fishes. It consists of two cavities, an 

 auricle, and a ventricle, provided with a thin membranous valve 

 between them. The former receives all the blood of the body 

 by four large vessels, viz. two veins conveying it from the head 

 and anterior parts ; one from the liver ; and one from the mus- 

 cles of the posterior portion of the spine, the organs of gene- 

 ration, and the other viscera of the abdomen. The first run 

 close to the spinal column, one on each side, and are joined 

 by a transverse branch opposite to the twelfth vertebra : they 

 afterwards separate, and proceed, one in a straight direction, 

 the other across the inferior surface of the oesophagus, to ter- 

 minate in the auricle. The posterior cava, which is the largest 

 of all, proceeds along the inferior surface of the spine, between 

 the kidneys, to its destination ; while the cava hepatica, after 

 piercing the pericardium at its posterior part, runs for some 

 distance within the cavity before it terminates in the auricle. 

 The ventricle is of a conical shape, of a reticulated appearance 

 internally, and possesses two sigmoid valves at the origin of the 

 branchial artery. The latter arises from it by an elongated 

 bulb, of an oval figure, and measures from two and a half to 

 three inches in length. It extends along the inferior surface 

 of the oesophagus, and divides, opposite to the posterior bran- 

 chial arches, into three branches of an equal size. Two of these 

 branches run, one on eacli side, between the fourth or poste- 

 rior arcli and the small bone connected with deglutition, as 

 far as the vertebral extremity of the inferior limb of the for- 

 mer ; and being there reflected backwards, unite at an acute 

 angle, opposite to the tenth vertebra, to form the aorta. The 

 third branch, which is the continuation of the artery, proceeds 

 along the under surface of the arches, and gives off, in its 

 course, a branch to the second and third of each side ; it then 

 runs forward as far as the us hyoides, and is ultimately expend- 

 ed upon the respiratory bladders. The small branches of the 



