124 DR. MARTIN BARRY ON FIBRE. 



Fig. 53. Chick in ovo ; incubated fifteen days. From the leg. Filament, seen with 

 an immense number of other filaments, forming a very large muscle- 

 fasciculus (par. 45). 



Fig. 54. Periwinkle. Interlacing spirals. The lower part of a was not very distinctly 

 seen on the left side. /3. Similar objects, but larger. They are in outline. 

 y. Seen with great distinctness (par. 45). 



Fig. 55. Scheme, illustrating the structure, apparently, of the objects figs. 40 a, 

 41 a, |3, 52, 54, 56, 83, 84, and of every object termed in this memoir a 

 filament, flat filament, or band, i. e. a " fibre" (pars. 13, 14). 



Fig. 56. Turtle. Portion of muscle from the heart. It is a filament, composed of 

 two interlaced spirals (par. 45) ; but very much larger than usual. At 

 the filament is broadest : at (3 it is narrower, perhaps from elongation : 

 at y it is twisted ; and it is the (narrow) edge of the filament that is 

 here seen (par. 44 Note). 



Fig. 57- Chick in ovo ; incubated fifteen days. Interlacing spirals, a. Two nuclei, 

 with orifices (" nucleoli"), in the space circumscribed by one of the 

 spirals (par. 44). 



Fig. 58. Tadpole, 65'". Four spirals visible on one side of the fasciculus ; in each of 

 which were seen two filaments (par. 42). An appearance of fibres cross- 

 ing one another (spirals entering into the formation of the investing 

 membrane ?) was observed at the outer part. They are not shown in the 

 figure. 



Fig. 59. Tadpole. From the tail. A small muscle-fasciculus, in which are seen 

 spirals surrounding objects, probably filaments, too minute to be ex- 

 amined in this state. On the left side, one of the spirals is ruptured, 

 (par. 42). 



Fig. 60. Scheme, showing the structure of objects illustrated by fig. 55, in an altered 

 state (see pars. 27, 38, 39). 



Fig. 61. Muscle-filament (" fibrilla") from the iris of a fish, on its flat surface 

 (par. 45). 



Fig. 62. Tadpole, about 6'". Sketch of the widened or brush-like extremities of two 

 ruptured fasciculi of muscle (par. 1 19 Note.) a. Two filaments (" fibrillse"). 

 The inner of these filaments presents its edge only. The outer filament 

 exhibits at the upper part, its flat surface ; and at the lower part, its 

 edge: i. e. this filament is twisted (par. 45.). Dots represent the situa- 

 tions of the other filaments in these two fasciculi. 



Fig. 63. Tadpole. Sketch of a fasciculus of muscle, broken off at the upper part. 

 The transverse and longitudinal striae, are represented by lines, except at 

 a, where the structure is delineated fully. This part shows the edge of 

 six filaments (" fibrillee") (par. 45). (8, /3, (3. These longitudinal striae 

 darker than the rest (par. 42). 



