THE STORY OF NINETEENTH-CENTURY SCIENCE 



but it was Bichat's exposition that gave currency to the 

 idea. 



Far more important, however, was another classifica- 

 tion which Bichat put forward in his work on anatomy, 

 published just at the beginning of the century. This was 

 the division of all animal structures into what Bichat 

 called tissues, and the pointing out that there are really 

 only a few kinds of these in the body, making up all 

 the diverse organs. Thus muscular organs form one 

 system ; membranous organs another ; glandular organs 

 a third ; the vascular mechanism a fourth, and so on. 

 The distinction is so obvious that it seems rather diffi- 

 cult to conceive that it could have been overlooked by 

 the earliest anatomists ; but, in point of fact, it is only 

 obvious because now it has been familiarly taught for 

 almost a century. It had never been given explicit ex- 

 pression before the time of Bichat, though it is said that 

 Bichat himself was somewhat indebted for it to his mas- 

 ter, the famous alienist, Pinel. 



Howeverthat may be, it is certain that all subsequent 

 anatomists have found Bichat's classification of the tis 

 sues of the utmost value in their studies of the animal 

 functions. Subsequent advances were to show that the 

 distinction between the various tissues is not really so 

 fundamental as Bichat supposed, but that takes nothing 

 from the practical value of the famous classification. 



ii 



At the same time when these broad microscopical dis- 

 tinctions were being drawn there were other workers 

 who were striving to go even deeper into the intricacies 

 of the animal mechanism with the aid of the microscope. 



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