From the Unconscious to the Conscious 



with those that we shall now examine. The problems of 

 embryonic and post-embryonic metamorphoses, and the 

 problem of so-called supernormal physiology, if we take 

 the trouble to look at them conjointly, enable us to affirm 

 that the classical concept of physical individuality is 

 erroneous, and that the living being is quite other than 

 a cellular complex. 



We shall probe to the quick the fundamental defect 

 of the ascending method which strives to adapt an 

 explanation to simple or relatively simple facts, while 

 evading the inherent difficulties of complex or relatively 

 complex facts. 



If we look at physiology as a whole and synthetically, 

 without putting aside these primordial difficulties; and, 

 a fortiori, if we give weight to them, then the concept 

 that results is undeniably and evidently quite opposed 

 to that which some have sought to deduce from mediocre, 

 narrow, and tentative analytical researches. 



3. THE PROBLEM OF EMBRYONIC AND POST-EMBRYONIC 



METAMORPHOSES. 



It is well known that embryonic and post-embryonic 

 development, far from being uniform, proceeds by a 

 series of metamorphoses. These sometimes retrace the 

 previous evolutionary changes of the species, and some- 

 times reflect the divergent adaptations realised during 

 larval life. Metamorphoses are common to all animals, 

 but are specially remarkable among those which have 

 a prolonged larval life after leaving the egg, such as 

 batrachians, molluscs, and annelids. By these changes 

 the development of the animal assumes successive forms, 

 very different from one another, before reaching the 

 definitive adult shape. These facts are a complete 

 negation of the classical theories on the building up of 

 the organism. 



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