Mar. 1901.] BOTANICAL SOCIETY OF EDINBURGH 47 



then, not on the physical and morphological structure of 

 protoplasm or its parts, but on the chemical constitution of 

 living substance, that is, on the structure of its molecules." 

 Chemical changes, as exemplified in dead matter, suffice to 

 explain the characteristic phenomena of life. 



The simplest living part imaginable is the biomolecule, 

 which differs in constitution in nowise from molecules of 

 other chemical compounds. The molecules are united together 

 by chemical affinity into molecular compounds (biomores), 

 the particles, granules, and microcosmes of the morpholo- 

 gical theories. The molecules constituting any biomore 

 form a little symbiotic system, in which the molecules 

 mutually aid each other. The biomores, again, are united 

 into larger groups in a tiuid or semifluid matrix, and form 

 living matter or bioplasm. Each mass of bioplasm forms 

 a symlDiotic system of biomores, called a biomonad. The 

 cell is a biomonad characterised by the possession of special 

 biomores of a particular chemical character. Symbiosis 

 plays a large part in this theory, and the author regards it 

 as the most important phenomenon of all biology, in which 

 must be sought the key to many important questions in 

 relation to living matter. 



To go into the theory in detail. 



The author clears the ground by stating in minute detail 

 his interpretation of the two most important vital pheno- 

 mena — assimilation and reproduction. It is just here, it 

 may be observed, that lies the crux of the whole matter 

 — accept the views on this point and all the remainder 

 inevitably follows. He enumerates all the known types of 

 chemical change, and then proceeds to argue that since 

 living substance contains no chemical element that does 

 not also occur in dead matter, the explanation of vital 

 phenomena (of a chemical nature) must be based on the 

 same types of chemical change as are found in dead 

 matter. Are the most characteristic and fundamental of 

 the vital phenomena — assimilation and reproduction — 

 which appear to lie outside the general laws of chemistry, 

 capable of explanation on any of the known types of 

 chemical change ? To this question, unlike most biologists, 

 the author replies in the affirmative. 



Assimilation is the phenomenon by which a living 



