INTRODUCTION 189 



consists in organising into cellular tissue the little masses of gelatinous 

 or mucilaginous material which she finds at hand under favourable 

 circumstances ; in filling these little cellular masses with fluids and in 

 vivifying them, by setting these contained fluids in motion by means 

 of the stimulating subtle fluids which are incessantly flowing in from 

 the environment ; 



2. That cellular tissue is the framework in which all organisation 

 has been built, and in the midst of which the various organs have 

 successively developed by means of the movement of the contained 

 fluids which gradually modifies the cellular tissue ; 



3. That the function of the movement of the fluids in the supple 

 parts of the living bodies which contain them, is to cut out paths and 

 establish depots and exits, to create canals and afterwards various 

 organs ; to cause variation in these canals and organs by means of a 

 diversity either in the movements or in the nature of the fluids which 

 produce and modify them ; finally to enlarge, elongate, divide and 

 solidify gradually these canals and organs by substances which are 

 formed and incessantly separated off from the essential fluids in move- 

 ment there ; substances of which one part becomes assimilated and 

 united with the organs while the other is thrown out ; 



4. That, lastly, the function of organic movement is not merely 

 the development of organisation, and the increase and growth of the 

 parts, but also the multiplication of organs and of the function which 

 they fulfil. 



After having expounded these great principles which seem to me 

 unquestionable truths although not hitherto recognised, I shall enquire 

 what faculties are common to all living bodies and consequently to 

 all animals ; I shall then pass in review the chief of the faculties which 

 are peculiar to certain animals but are not possessed by the rest. 



I venture to affirm that grave injury results to the progress of 

 physiological knowledge by the thoughtless supposition that all 

 animals without exception possess the same organs and enjoy the 

 same faculties ; as though nature were everywhere forced to employ 

 the same methods to attain her end. Seeing that nothing more than 

 an active imagination is needed for setting up principles if we do 

 not pause to consider facts, it is an easy supposition that all living 

 bodies possess the same organs and hence enjoy the same faculties. 



Another subject which I must not neglect in this second part of my 

 work is the question of the immediate results of life in a body. Now 

 I am in a position to show that these results give rise to combinations 

 between principles which, except for this factor, would never have been 

 united together. These combinations accumulate more and more 

 according as the vital energy increases, so that in the most perfect 



