PHYSIOLOGY Ixxv 



reproduction, and Lamarck's revival of the " aura vitalis " 

 or semi-spiritual theory constitutes a grave indictment of 

 his scientific judgment. It is possible, however, that he 

 was not aware of %)allanzani's experiment, though he 

 mentions that savant in another connection. 



Lamarck's chemistry was that which prevailed before 

 Dalton had formulated the Atomic theory, and is con- 

 sequently by no means easy for a modern reader to 

 "understand. It is enough, however, to observe that he 

 regarded the sum-total of living things as being (as indeed 

 they are) an immense and ever-active laboratory. He held 

 that all substances, organic and inorganic, were the produce 

 of organisms. In their bodies, he says, are elaborated all 

 tnown complex substances ; from their decomposing remains 

 spring all inorganic and mineral substances. How the first 

 gelatinous or mucilaginous corpuscle came to be lying about, 

 when there was nothing for it to lie about on, is unexplained : 

 but perhaps it is unfair to approach too nearly to first causes. 



The subtle invisible fiuids which become the " exciting 

 <iause " of life, and hence of chemical synthe&is in organic 

 matter, behave in exactly the opposite way in inorganic 

 matter, which they ever tend to decompose into its elements 

 or " principles." Lamarck's theory as to the causes of 

 death is not with out interest. The solid parts of the organism 

 are composed of various substances, and are subject to a 

 constant metaboUsm. In the course of katabolism, the less 

 sohd and more volatile parts would be given off most freely. 

 In anabolism, the new substances brought would be only of 

 the average consistency. Since the most volatile parts are 

 thus constantly being replaced by less volatile parts, the 

 substance of the organism tends to an increasing rigidity 

 and hardness ; it can support only a diminished distention 

 from orgasm, and finally becomes incapable of the further 

 maintenance of life. 



The rest of Lamarck's physiology is of no special interest. 

 He held that there are certain " faculties " common to all 

 living bodies, such as growth, nutrition, reproduction ; and 



