ON LIFE AND ORGANISATION. 289 



must henceforward be prepared to employ in his researches 

 the matheniatico-experimeutal methods of physical science. 



The advance which has recently been made in ascertaining 

 the structure and actions of the living organism considered as 

 a chemico-physical system, consists — 1st, of the recognition 

 of the depth and extent of chemical action in the economy ; 

 2d, of the evidence latterly afforded of the primary importance 

 of the electrical force in the organism generally, but more 

 especially in the actions hitherto considered more essentially 

 vital ; "3d, of the detection of the connection between the 

 chemical and electrical actions of the organism, and its recently 

 discovered microscopic structure ; 4th, of the successful 

 efforts made to determine by phy si co-mathematical methods 

 the precise forms and reciprocal mechanical actions of the 

 different parts of the organism. 



The second group of subjects which at present engages the 

 attention of physiologists, is the investigation of the numerous 

 forms of organisms, embryo and adult, viewed as modifications 

 of certain abstract organic forms, or ideal types. These subjects 

 constitute morphology, properly so called. Although an 

 essential element of physiological science, morphology is only 

 of recent growth. Its development was retarded for many 

 years by the influence which results from the fundamentally 

 peculiar nature of the subject. It is peculiar in this respect, 

 that it does not contemplate at all the actions or uses of parts, 

 but only their presence, their forms, and their relations in 

 any one species of organism as compared with other organisms, 

 and with a view to the determination of the general plan, 

 according to which they have all, each after its kind, been 

 constructed. The influence which has retarded the progress 

 of morphology, as it lias retarded other departments of science 

 and philosophy, is that difficulty which the generality of minds 

 experience in conceiving the possibility of any phenomenon 

 or action having a double relation — of its being conditioned, 



