Such was the view held by Claude Bernard. He never varied on this point. _Irritability_, said he, is the property possessed “by every anatomical element (that is to say, the protoplasm which enters into its constitution) of being stimulated into activity and of reacting in a certain manner under the influence of the external stimuli.” He could not claim that this was a distinguishing characteristic between living bodies and brute bodies, and that all the less because he always tried to efface on this point the distinctions which were current in his time, and which were established by Bichat and Cuvier. And so also Le Dantec does not seem to have thoroughly grasped the ideas of the celebrated physiologist on this point when he asserts, as if he were thereby contradicting the opinion of Claude Bernard and his school, that irritability is not something peculiar to living bodies.[17] [17] These ideas are clearly brought to light in a series of articles in the _Revue Philosophique_, published in 1879 under the title of “La problème physiologique de la vie,” and endorsed by A. Dastre in his commentary on the _Phénomènes communs aux animaux et aux plantes_. CHAPTER V. THE SPECIFIC FORM. ITS ACQUISITION. ITS REPARATION. § 1. Specific form not special to living beings—Connected with the whole of the material conditions of the body and the medium—Is it a property of chemical substance?—§ 2. Acquisition and re-establishment of the specific form—Normal regeneration—Accidental regeneration in the protozoa and the plastids—In the metazoa. § 1. THE SPECIFIC FORM. _The Specific Form is not Peculiar to Living Beings._—The position of a _specific form_—the acquisition of this typical form progressively realized—the re-establishment when some accident has altered it—these are the features which we consider distinctive of living beings, from the protophytes and the lowest protozoa to the highest animals. Nothing gives a better idea of the unity and the individuality of the living being than the existence of this typical form. We do not mean, however, that this characteristic belongs to the living being alone, and is by itself capable of defining it. We repeat that this is not a case with any characteristic. In particular the _typical form_ belongs to crystal as well as to living beings.