1 36 Dr. Hodgkin and J, J. Lister's Microscojpical Observations 



we are very far from believing that tliese or any other mode of 

 aggregation which the particles of the blood may be observed 

 to assume, ought to be regarded as at air analogous to the 

 process which nature employs in the formation of the different 

 tissues. 



I some yeai-s ago briefly stated this opinion, which I was in- 

 duced to form a priori*; but I may now appeal to facts in sup- 

 port of it. 



In proceeding to offer a very short sketch of the result of 

 our inquiries into the microscopic appearances of some of the 

 animal tissues, I do so with one painful feeling, which I shall 

 perhaps be excused from expressing. It is, that I am under 

 the necessity of differing from my excellent and intelligent 

 friend Dr. M. Edwards. It was the knowledge of his talents 

 and address, and of the patience and care with which he made 

 those investigations, which he has related, which induced me 

 to enter into the examination of a question, which I had already 

 regarded as settled in the negative. And though J. J, Lister 

 and myself, in repeating the observations of Dr. M. Edwards, 

 have arrived at widely different conclusions, I am confirmed 

 in the conviction, that he described what he saw, and tliat he 

 only saw amiss through the imperfection of his instruments. 

 The idea of the globular structure of the different tissues is 

 however by no means peculiar to Dr. Edwards, and to those 

 micographers to whom I have already frequently alluded. Dr. 

 Edwards, in the papers to which I refer, has employed much 

 erudition to show that similar views had been taken, with re- 

 spect at least to some of the tissues, by Hooke, Leeuwenhoeck, 

 Swammerdam, Stuart, Delia Torre, Prochaska, Wenzel, Du- 

 trochet, and Clocquet. 



Muscle. — The muscular tissue may be easily seen with the 

 naked eye, or with thie assistance of a comparatively feeble lens, 

 to be composed of bundles of fibres, held together by a loose 

 and fine cellular mei nbrane, and these fibres are again seen to 

 consist of more minute fibrillae. It is difficult to push the me- 

 chanical division mu ch further; for the softness of the muscular 

 substance is such, tliiat it either crushes or breaks off, rather 

 than admit of furth-er splitting. If a piece of one of the most 

 delicate of the fibril lae last arrived at be placed on a piece of 

 glass in the field of the microscope, lines may be seen parallel 

 to the direction of the fibre, which show a still further division 

 into fibres. Although no trace of globular structure can be 

 detected, innumerable very minute, but clear and fine, parallel 

 lines or striae ma}' be distinctly perceived, transversely mark- 



• rjrfr" Thesin de Absorbendi Functione." Edin. 1S2.3. 



ins 



