}826.] Philosophical Transactions for 1826, Tarts I, and II, 135 



mucus which surrounds them, and forms them into fasciculi, 

 that it was only under water he could separate an integrant 

 fibre for examination in the field of the microscope. 



*^ In its mechanism, be found it to correspond with the ner- 

 vous fibre of a ganglion, differing only in the size of the 

 globules, which were larger than those of the fibre in the 

 ganglion in the proportion of ^toVo^ parts of an inch to -3^0-0 and 

 ToW parts. 



*' The elastic transparent jelly uniting the globules together, 

 had not the same elasticity as in the nervous fibre, so that it 

 could not be drawn out from the contracted state to double itfi 

 length without breaking, 



" The muscular fibre of a trout was treated in the same way, 

 and the result was the same ; the fibres were however more 

 brittle than those in the bullock's neck. 



'* From these facts, in addition to those communicated in the 

 examination of the structure of gangUons, it is at last ascer- 

 tained, that the structure of the fibres of nerves in general, and 

 those peculiar to ganglions, as well as those that compose 

 muscles, is so far the same, that they consist of single rows of 

 globules united together by an elastic gelatinous transparent 

 matter ; they differ however in the size of the globules, and the 

 degree of elasticity of the medium by which they are united ; 

 so that a less power will elongate a nerve than the fibres of a 

 muscle, and to a greater extent, and it will restore itself with 

 more velocity to a state of rest. 



*' This structure of nerves and muscles, I consider to be de- 

 monstrated in the annexed drawing ; since I cannot believe Mr. 

 Bauer has been led into any error upon this occasion ; as no 

 error has been detected in his microscopical observations for so 

 many years continued, and the accuracy of his representations, 

 of what he has seen, no one can doubt. 



" It is a curious confirmation of the acuteness of his eye, and 

 the accuracy of his glasses, that Leuwenhoek, who used a single 

 microscope, and says it is the best that can be made, since the 

 magnifying glass is the smallest speck that can be seen, declares 

 a muscular fibre to be made of globules less than the red glo- 

 bules of the blood ; and Dr. Monro of Edinburgh, who pub- 

 lished his microscopical observations on nerves and muscles, in 

 the year 1783, made chiefly in the solar microscope, goes so far 

 as to consider muscular fibres to be the continuation of nervous 

 fibres, and gives an engraving of the mode in which the one ter- 

 minates, or is lost in the other. Dr. Monro, it is evident, had 

 never seen a single fibre either of a nerve or muscle, only fasci- 

 culi of them, and found them so much alike as to be led to con- 

 sider them the same. Both Leuwenhoek and Monro, from the 

 want of a micrometer, were left to guess at relative dimension, 

 and in such guesses were often very unsuccessful. 



