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yellow Fasciated tissue, forming numerous oval and round areas, of 

 very unequal size, and disposed without order or reference to the 

 open areas of the neighbouring layers, either above or below. When 

 the fasciae are wide, they appear membranous and unevenly plicated 

 within the margins, which are usually rounded or thickened ; but 

 when they are narrow they assume a swollen and ligamentous appear- 

 ance, as represented in PI. xviii. fig. 7. 



At the base of this tissue there is a thin membrane of an even tex- 

 ture, which presents a finely granulated surface when viewed with a 

 power of 600 linear. Immediately beneath this is seated the tissue, 

 which appears to me to be equivalent to the " white fibrous element 

 of areolar tissue " of Bowman. With a linear power of 250 it has 

 the appearance represented in PI. xviii. fig. 8. With this power it 

 seems as if the striations were produced by a series of parallel con- 

 tractions, of an upper and softer stratum of the membrane, as the 

 lines of division are not continuous, but frequently merge into each 

 other, and the edges of the supposed fibres appear ragged and un- 

 conformable ; but upon examining it with a microscopic power of 

 1020 linear, the object presented a widely different aspect, and the 

 striations now appear as if they were produced by lines, composed 

 of parallel fasciculi of minute tortuous vessels, buried in the sub- 

 stance of a comparatively thick membrane ; but I am induced to be- 

 lieve that this is not in reality the structure of the tissue, but that 

 the fasciculated appearance of the vessels is due to the tissue being 

 composed of numerous thin layers of basement membrane, each 

 having a series of single vessels running parallel to each other, and 

 that the lines of vessels are conformable with each other in the whole 

 of the membranes of which the tissue is composed ; for in several 

 parts of the preparation I am describing, there are fragments of ex- 

 ceedingly thin membranes, which project from the torn edges of the 

 fibrous tissue, and which are furnished with parallel lines of single 

 vessels. The courses of these vessels through the tissue are not in 

 undeviating lines, but slightly undulating, so that a series of them 

 would naturally give the confused and tortuous appearance which 

 exists in the membrane, in its natural and undisturbed condition. 



It would appear from Mr. Bowman's description, which I have al- 

 ready quoted, that he saw similar minute vessels in the corresponding 

 tissue of the mucous membrane of the human subject, for he says, — 

 " Beside these bands, commonly called fasciculi, there are some finer 

 filaments of the utmost tenuity, which seem to take an uncertain 

 course among the rest." When the shell-tissue is torn at right angles 



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