28 Observations nn the Natural tiistorij 



bristle ; 6, the left ovariicm, containing minute ova, and 

 drawn to one side to display the kidney underneath ; c, a 

 portion of the oviduct straitened by the action of the spirits; 

 d, the left kidney ; e, the ureter running along its margin, 

 and terminating with the oviduct in the rectum ; f, a por- 

 tion of the left air-bladder, in this instance remarkably en- 

 larged ; the corresponding one of the right side was very 

 small. 



Plate VI. Fig. 4. The cranium laid open, to shew the cerebral 

 mass and certain nerves springing from it ; a a, the two hemi* 

 spheres of the cerebrum ; 6, the cerebellum ; c, the medulla 

 oblongata ; d, the right olfactory nerve ; e, the origin of the 

 fifth pair of nerves ; Jl the vestibule of the organ of hearing 

 laid open, in which the little sac is seen, and the origin of 

 the acoustic nerves ; g^ the facial nerve ; h, the entrance of 

 the carotid into the cranium, from which springs the opthal- 

 mic going to the eye (n) ; m, the origin of the par vagum. 



Plate VI. Fig. 5. Profile of the head and part of the trunk ; 



a, the external aperture of the nostrils surrounded by pores ; 



b, the doubling of the inferior lip, which is in part covered 

 by the superior ; c, the swelling or protuberance produced 

 by the heart. 



Plate VII. Fig. 1. A male proteus laid open, to exhibit the re- 

 lative size and position of the viscera; a, the heart, with 

 its pericardium, opened and turned back ; bbb, the liver 

 drawn aside, to shew the viscera beneath it ; c, the stomach ; 

 d, the alimentary canal ; e, the spleen ; J", the pancreas ; 

 g, the testicle of the left side ; h^ a part of the left kidney ; 

 i, the urinary-bladder ; k, the left air-bladder, with its tube, 

 opening into the conical cavity above ; Z, the anus or cloaca ; 

 m, the sinus of the vena cava. 



Plate VII. Fig. 2. a, the heart reversed and turned upward ; 

 b, the short conical canal cut longitudinally, which commu- 

 nicates anteriorly with the glottis, and posteriorly with the 

 cavity from which the two tubes, (cc) terminating in the 

 air-bladder, proceed. 



Pkte VII. Fig. 3. Head of the proteus viewed from below, eight 

 times greater than natural, displaying the circulating and res- 

 piratory systems ; ffl, the heart ; 6, the arterious trunk spring- 



