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refractive lines. Two or more of these layers occur in a section ; and 

 although the bundles composing each layer are placed on a level 

 plane, and pursue a similar direction, they do not lie in immediate 

 contact. Each roll, indeed, is separated from its fellow by a parallel 

 depression equal in breadth to its own diameter, and about half 

 as deep. The bottom of each interspace is filled up by one of the 

 bundles composing the subjacent layer, and by the ends of the longi- 

 tudinal fibres. Each of these cells or bundles of fibrous tissue 

 is smooth on its exterior, of a yellowish colour, oily, and composed, 

 apparently, of numerous molecular fibres, imbedded in a transparent 

 structureless stroma or matrix. These molecular fibres appear to 

 possess a longitudinal arrangement ; but by long maceration in water, 

 or by the addition of weak ammonia, the separate bundles swell up, 

 become pale and granular, and lose every appearance of being com- 

 posed of longitudinal fibres. These changes are more rapidly 

 and decidedly induced by the action of weak acetic acid. On the 

 addition of this re-agent, the separate bundles almost instantly swell 

 out to nearly double their original size, and become more regularly 

 rounded, exceedingly pale and studded with granules. Simulta- 

 neously with the occurrence of these changes, a number of persistent 

 nuclei make their appearance along the margins of each bundle. 

 These are small, transparent, of a yellowish green colour, and oval or 

 somewhat elongated in shape. In this condition, each bundle ap- 

 pears as a rounded, structureless mass, studded with innumerable 

 black points. These points or granules are arranged in a transverse 

 direction, and it is in that direction too that the bundles when in this 

 state are generally cracked or fissured. When greatly diluted acid 

 was employed, the appearance produced in the bundles was very pe- 

 culiar. Each bundle seemed to be made up of a series of smaller 

 bundles of molecular fibres, twisted in a spiral direction, and imbedded 

 in, or connected to each other by a transparent, structureless matrix. 

 This latter appearance was exceedingly common, and could be at any 

 time induced by the careful reaction of acetic acid. 



These bundles are retained in their position partly by a fine, fila- 

 mentous tissue, which surrounds them in every direction, but princi- 

 pally by numerous arctuous bands which proceed onwards from the 

 areolar tissue beneath the germinal membrane, pass round the inner- 

 most fibrous bundle, and become firmly connected with the arctuous 

 bands of other layers. These bands are composed of elastic, fibrous 

 tissue, and in their progress inwards give off subsidiary bands, which 



