No. 7.] AMERICAN ASSOCIATION. 391 



" Because life is unlike other properties ut' matter, it by no 

 means follows that it is not a property of matter. No dictum is 

 more absolute in science then the one which predicates properties 

 upon constitution. To say that this property exhibited by proto- 

 plasm, marvellous and even unique though it be, is not a natural 

 result of the constitution of the matter itself, but is due to an 

 unknown entity, a tertiiim quid, which inhabits and controls it, 

 is opposed to all scientific analogy and experience. To the state- 

 ment of the vitalist that there is no evidence that life is a 

 property of matter, we may reply with emphasis that there is 

 not the slightest proof that it is not. 



'' Chemistry tells us that complexity of composition involves 

 complexity of properties. The grand progress which Organic 

 Chemistry has made in recent times has been owing to the distinct 

 recognition of the influence of structure upon properties. Iso- 

 merism is one of its most significant developments. The 

 number of possible isomers increases enormously with the 

 complexity of the molecule. Granted that we now know several 

 of the proteid group of substances : how many thousand may 

 there be yet to know ? Bodies of such extreme complexity of 

 constitution may well have an indefinite number of isomers. 

 Not only does chemistry not say that there cannot be such a 

 thing but she encourages the expectation that there will be yet 

 found the precise proteid of which the changes of protopU\sm 

 are properties. The rapid march of recent organic synthesis 

 makes it quite certain that every distinct chemical substance of 

 the living body will ultimately be produced in the laboratory ; 

 and this from inorganic material. Given only the exact 

 constitution of a compound, and its synthesis follows. When, 

 therefore, the chemist shall succeed in producing a mass con- 

 stitutionally identical with protoplasmic albumin, there is every 

 reason to expect that it will exhibit all the phenomena which 

 characterize its life ; and this equally whether protoplasm 

 be a single substance or a mixture of several closely allied sub- 

 stances." 



Address of Professor Alexander Agassiz on Paleon- 



TOLOGICAL AND EmBRYOLOGICAL DeVELOPMONT. 



Prof, xlgassiz read a paper on Paleontological and Embryological 

 Development. He said : " Since the publication of the ' Pois- 

 sons Fossiles' by Agas.siz and of the 'Embryologie des Salmon- 



