anti carrangeineiit of' tlie contractile elements of tliese large fibres is 

 better elucidated by regarding the cross-sections figured in fig. 2, 4, 

 and 5 than by a long-winded description. Es])ecially in the transverse 

 sections of the larger muscle-fibres of the sphincter pupiilae of full- 

 grown fowls this arrangement of the sarcostyles in liattened and 

 curved bundles is clearly shown. 



The sarcoplasm between the folded and curved sarcostyles is in 

 most cases of a very loose reticular slightly granular appearance. 

 Outside the column of fibrilbundles and platelike bands the sarco- 

 plasm is generally of a more coarsely granular structure and sur- 

 rounds the contractile elements on all sides, often in a thick layer. 

 .Sometimes this granular appearance is seen throughout the whole 

 of the transverse section of a mnscle-fiber. At intervals this layer of 

 sarcoplasm lying outside the column of sarcostyles is so thick, that 

 it not only surrounds the bundle of sarcostyles at all sides, but is 

 seen projecting beyond the line of the surface of the fibre, forming 

 a sort of protuberance on the side of the tibre (fig. 2, fig. 6) ; this 

 accumulation of sarcoplasm always contains several nuclei ; which 

 however, are found also here and there in the loosely reticulated 

 sarcoplasm between the sarcostyles (fig. 5). These sarcoplasmatic 

 protuberances may be compared with the granular expansions first 



is.. 



Fig. 0. Fig. 7. 



Fig. 6 and 7 Longituiiinal sections of striated muscle-fibres of the iris of 

 the fowl's eye 



