THE CELL-THEORY 245 



before any successful attempt can be made to establish the true laws 

 of function, or to build the science of physiology upon an exact 

 foundation. 



Herein lies, consciously or unconsciously to their authors — for the 

 man of genius is such, in virtue of having true and just tendencies 

 and impulses, of which he often can give himself no logical account — 

 the secret of the repeated attempts which have been made from the 

 time of the very fathers of biology, to found what we now call the 

 doctrine of general anatomy or histology, which is, in other words, the 

 exhaustive anatomical analysis of organized bodies. That animals and 

 plants, complex as they may appear, are yet composed of compara- 

 tively few elementary parts, frequently repeated, had been noticed by ^ 

 the profound intellect of Aristotle ; and Fallopius tells us that Galen r^ 

 had attained to still more clear and definite conceptions with regard 1 

 to these " partes similares " or " simplices." ^ ~ 



" Galenus per simplices partes eas intelligit quae non constant ex 

 dissimilibus substantiis, in quas resolvitur corpus humanum, nee ultra 

 datur progressio et istae partes dicuntur simplices quia cum ad hoc 

 ventum fuerit in resolutione corporis humani, non amplius progredi 

 possumus." (p. 103.) 



Such, indeed, must be the definition of elementary parts at all 

 periods of science — they are ultimate, because we can go no further ; 

 though it is of course a very different matter whether we are stopped 

 by the imperfection of our instruments of analysis, as these older 

 observers were, or by having really arrived at parts no longer 

 analyzable. 



The celebrated professor of Modena, whose words we have just 

 cited, was one of the first of those who carried the light shed by the 

 revival of letters into the region of medicine and its allied sciences ; 

 and his work ' De Partibus Similaribus,' from which they are taken, 

 must excite the admiration of every modern reader, not merely by 

 the critical acumen and original genius which it displays, but by the 

 scientific and absolutely accurate manner in which the whole subject 

 of general anatomy is handled. 



The classes of " partes similares," or tissues, of which he treats, 

 are bone, cartilage, fat, flesh, nerve, ligament, tendon, membrane, vein, 

 artery, nails, hairs, and skin ; and he examines and details under each 

 head the minute structure, so far as it was accessible to his means of 

 investigation ; the chemical and physical properties (expressed, of 

 course, in the language of the day), and even the peculiarities 



^ Terms by no means always convertible, but Avhich may for the present be taken to 

 be so. 



