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been generally concluded that this fibre is confined to the upper 

 portion of the tube, Professor Miiller, Dr. Schwann, and Mr. Skey 

 informing us that the striated muscular fasciculi are eitlier confined 

 to this part of it, or belong only to the muscles of the pharynx, while 

 MM. Ficinus and Valentin have been led to assign a much more 

 extensive range to the fibre in question. 



" From a somewhat attentive investigation of this subject during a 

 residence in the country last spring, and without any more inform- 

 ation as to what had been done by others than is to be found in Mr. 

 Skey's paper, it appeared to me not only that the muscular fibre of 

 animal life extended much further towards the stomach in certain 

 brutes than in man, but that there was also a remarkable difference 

 in this respect even among different genera of animals. Hence I 

 propose to communicate to the Society a short account of my obser- 

 vations, with the impression that they will tend as well to reconcile 

 the discordant results of others, as to direct attention to a field of 

 inquiry which may prove of much interest, both as regards the phy- 

 siology of the muscular tissue and of an imjiortant part of the ali- 

 mentary apparatus. 



"1. In the Dog (Canis familiaris, Linn., and C. familiar is var. 

 Australasia, Desm.) the muscular sheath, from its commencement 

 to its termination in the stomach, was found to be composed entirely 

 of distinct fibres everywhere marked with the striae, which appeared 

 to be of two distinct sizes, without intermediate gradations. Of the 

 largest, two and a half or three occupied a micrometer space of 

 l-4000th of an inch, while five of the smaller were required to cover 

 the same extent, the latter presenting a much more acute appearance 

 than the former; so the large striae were from l-10,000th to 

 l-12,000th of an inch broad, and the small marks l-20,000th. 

 The fibres were of the same diameter as those of the sartorius muscle, 

 both being larger than in the heart of the same animal. 



" 2. In the Fox (Canis Vulpes, Linn., and Canis Vulpes, var. Ame- 

 ricanus), to within half an inch of its termination it was composed 

 wholly of the striated muscular fibre, and this structure, mixed with 

 the muscular fibre of oiganic life, extended as far as the stomach. 

 The diameter of the striated fibre, or bundle of ultimate filaments, 

 was from l-666th to l-333rd of an inch, which much exceeds the 

 magnitude of the fibre in the heart of the same animal. 



" In the Silvery Fox {Canis argentatus, Desm.) the striated fibres 

 were abundant to within half an inch of the termination of the gul- 

 let : in the Arctic Fox (Canis lagopus, Linn.) they were detected to 

 its end, though in the former they could not be seen so near to the 

 stomach . 



" 3. In the common Otter (Lutra vulgaris, Desm.), the striated 

 fibres were detected abundantly to within half an inch of the cardiac 

 end of the gullet. The fibres were from l-800th to i-500th of an 

 inch in diameter. In the heart they had a diameter varying from 

 l-2000th to 1-1 143rd of an inch. 



" 4. In the Domestic Cat (Felis Catus, Linn.) the muscular sheath 

 of the oesophagus consisted wholly of striated fasciculi to about a 



