128 



fibre was almost entirely of the striated kind, there being but very 

 little of the muscular fibre of organic life, even close to the stomach. 

 The fascicles measured from l-888th to l-333rd of an inch in di- 

 ameter. 



" 17. In another Coati (Nastta nifa, Desm.) the striated fibre ex- 

 tended to the stomach ; the outer layer was composed entirely of 

 the muscular fibre of animal life, the fibres being longitudinal, and 

 easily separable from the inner layer, which latter near to the stomach 

 was composed of the muscular fibre of organic life. 



" 18. In the Sloth Bear (Ursus labiatus, Blainville) the muscular 

 tunic of the gullet was remarkably strong and red, being about an 

 eighth of an inch thick in the neck, and increasing to a fourth of an 

 inch near the stomach. The striated fibre was detected throughout, 

 and extended some distance on the cardiac end of the stomach. 

 The fibres were generally large, viz., about l-400th of an inch in 

 diameter; in the heart from l-2000th to 1-lOOOth. 



"19. In the Capuchin Monkey (Cebus cajjucinus, Desm.) the stri- 

 ated fascicles were found abundantly, mixed with the muscular fibre 

 of organic life, two inches from the cardiac end of the oesophagus. 

 The fibres measured from l-800th to l-500th of an inch in di- 

 ameter. 



" 20. In the Lemur (L. Albifrons, Desm.) no striated fibres could 

 be seen within an inch and a half of the termination of the gullet. 

 In the Green, Grivet, Mangabey, and Rhesus Monkeys (Cercopithe- 

 cus Sabaus, C. grisep-viridis, C. jElhiops, and Macacus Rhesus), the 

 striae could not be observed within an inch and a quarter of the car- 

 dia, though several well-marked fasciculi were seen in this situation, 

 presenting a homogeneous or very irregular and slightly granular ap- 

 pearance, as if not composed of primary fibrils. An inch further 

 from the stomach the striated fasciculi were abundant. In the Dog- 

 faced Baboon (Cynocephalus Anubis,) Mr. Siddall could only trace 

 the striated fibres as far as three inches and a half from the stomach ; 

 in a Gibbon Monkey f he saw them no nearer to the cardia than an 

 inch and a half; and in a Barbary Ape the striated fibre was lost on 

 the gullet two inches from the stomach. 



" Professor Miiller assures us that ' the third act of deglutition is 

 perfectly involuntary, being performed by the muscular fibres of the 

 oesophagus, which are not in the slightest degree capable of voluntary 

 motion.' If this statement be correct, some of the facts adduced in 

 this paper are remarkable, since they are examples of complete iden- 

 tity of structure between the muscular fibres of the last portion of 

 the gullet and the known muscles of voluntary motion ; and this 

 identity, according to my observations, is not deduced from one ap- 

 pearance alone, but in several instances from a combination of cha- 

 racters, which I am not aware that any perfectly involuntarj' muscle 

 hitherto described presents; i. e. the ultimate filaments formed into 

 fasciculi, considerably larger than in the heart, well-defined, agreeing 



f To the csBcum of this Gibbon there was an Appendicula, which was 

 not the case in any of the other Quadrninann mentioned in this paper. 



