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it contains two species of papillae distinct in their structure, cor- 

 responding to the conical and fungiform papillae of man. 



In the present communication he describes the result of his fur- 

 ther researches on the frog's tongue, principally with regard to the 

 ultimate termination of the nerves in the papilla and the precise 

 nature of the functions of these papillae in the act of taste, and de- 

 monstrates a similar disposition of the nervous extremities in man 

 and the rest of the mammiferee. 



After giving a brief account of the researches of former ana- 

 tomists, he proceeds to state his method of preparing the frog for 

 examination, which consists in rendering it insensible by exposing 

 it to the vapour of ether or of various other volatile agents. The 

 tongue is then expanded so as to render it perfectly transparent. 

 The conical papillae he describes as small cones, sometimes simple, 

 sometimes compound. They are composed of globular, or wedge- 

 shaped epithelial cells, generally with a medullary stem running up 

 the centre, giving off small processes to the separate epithelial cells. 

 Each of the papillee presents, near its summit, a small aperture. The 

 fungiform papillae are distinguished from the former by their glo- 

 bular shape, larger size, and above all by the existence of a coil of 

 capillary vessels within them, containing blood in a state of active 

 circulation. At their summit or at their sides, the vascular coils are 

 extremely superficial and merely covered by an exceedingly thin 

 membrane* Besides the blood-vessels, these papillae are invariably 

 found to contain a nerve and also muscular fibres. The nerve con- 

 sists of about eight or ten simple tubules. At the base of the pa- 

 pillae it forms several loops, and afterwards ascends between the 

 capillary vessels towards the summit of the papillae, where its tubules 

 diverge and terminate in abrupt extremities. The author terms 

 that part of the papillae where the membrane is so attenuated, and 

 where the vessels ramify and the nerves terminate, the neuro-vas' 

 cular area ; the muscular fibres ascend into the papilla in the same 

 direction as the nerves, and after nearly reaching the summit, are 

 lost in the tissue surrounding the neuro-vascular area. The nerves 

 of the conical papillae, contrary to the former, never terminate in 

 abrupt extremities, and consist of a network of nearly single tubules. 

 Neither the nerves nor the vessels of these papillae ascend into their 

 interior, but are only spread out at their base. 



The author deduces from these and other observations which are 

 minutely described in his paper, that the fungiform are the papillae 

 of taste and the conical those of touch. He considers that by rea- 

 son of the thinness of the membrane at the neuro-vascular area, a 

 sapid substance must quickly traverse it ; the nerves immediately 

 beneath, like the spongioles of the roots of a plant, being acted upon 

 by the sapid substance, convey the sensation of taste to the brain. 

 The active circulation in the capillaries at the same spot appears to 

 be for the purpose of removing by endosmosis the sapid substance 

 from the nerve so as to render it capable of receiving a fresh im- 

 pression. A further peculiarity exists with respect to these papillae, 

 which is that they present at their surface an active ciliary move- 



