STRIATED MUSCULAR FIBRE IN MAMMALIA. 
257 
Fig. 8 b. A smaller specimen from a foetal pig, 2^ inches long. 
Fig. 9 a. Fibre from a foetal pig, 4 inches long. Nuclei in progress of dissolution. 
Breadth of fibre isVo th of an inch. 
Fig. 9 b. Fibre from the same pig, extending ; remaining nuclei and granules sepa- 
rating. Breadth of fibre wg^th of an inch. 
Fig. 9 c. Fibre from a foetal pig, 5 inches long. Nuclei not separated, but perishing 
in their places. Breadth of fibre of an inch ; of lateral bands 3 - 1 -ooth 
of an inch. 
Fig. 9 d. Fibre from a foetal pig, 5^ inches long. Nuclei broken up into clusters of 
granules. 
Fig. 9 e. Fibre from the same pig, extending. Breadth of fibre rs^jo th of an inch. 
Clusters of granules ^oVo^h of an inch apart. 
Fig. 9 f. Fibre from the same pig, still further extended. Clusters of granules 
separating and elongating. Breadth of fibre iwoth of an inch. 
Fig. 9 Fibres from the same pig, showing different progress of development in 
different parts. Nuclei breaking up into granules. 
Fig. 9 h. Fibre from a foetal pig, 3^ inches long. Distinction between lateral bands 
and centre well marked, faint appearance of striae in bands. Breadth of 
fibre -joVofh of an inch. Nuclei round, 4 - 5 ^ 0 - o th of an inch, separating, and 
about 1 smoo th of an inch apart. Breadth of bands g^^th of an inch. 
Fig. 9 i. Fibre from a foetal pig, 4 inches long. Shows unequal rate of development 
in different portions. 
Fig. 10 . Fibre from a foetal pig, 3| inches long. Nuclei separated; striae visible; 
breadth of fibre 3 -^^th of an inch. 
Fig. 11a. Fibre from a foetal pig, 8 inches long ; showing the method of increase by 
external nuclei in various stages. 
Fig. 1 1 h. Another fibre from the same pig. 
Fig, 11 c. Another fibre from the same specimen. Striae well marked. These fibres 
vary in diameter from ^o^o^h to of an inch. 
Fig. 1 1 d. Fibres from the same pig, after the addition of citric acid. 
Fig. lie. Free nuclei from the same specimen. 
Fig. 12. Fibres from a pig at the period of birth. 
Fig. 13 a. Fibre from a foetal pig, 5 inches long. Primary nuclei separating. In- 
crease by external nuclei. Breadth of fibre aoVo th of an inch. 
Fig. 13 b. Fibre from a foetal pig, 4 inches long, increasing by means of external 
nuclei. Breadth of fibre from "s oVo th of an inch. 
Fig. 14. Fibre from foetal pig, 2 ^ inches long, showing irregular rate of development. 
At one extremity the nuclei have scarcely become arranged in a linear 
series ; while at the other the nuclei have separated, and the striae are 
faintly visible. 
The figures just described have been drawn from the fibres of the foetal pig. 
