ON LIFE AND ORGANISATION. 287 



logical research in Germany could only have been induced 

 by the influence of an intellect like that of Johannes Miiller, 

 which is equally at home in the domains of the natural, 

 physical, and psychological sciences. 



There are, therefore, certain subjects of inquiry which at 

 certain epochs in their progress are obstructed by peculiar 

 difficulties. Such an epoch occurs when one subject is about 

 to merge into another, or when a particular subject, complex 

 in its nature, has reached that stage in its progress at which 

 it must henceforward demand for its investigation, two or more 

 fundamentally distinct modes of inquiry. At any epoch of this 

 kind, in the progress of any science, an attempt should be made 

 to determine its present position, to define its real obstacles, 

 and to ascertain whether the previous mode of inquiry had 

 involved all the fundamentally necessary methods of research. 



The science of organisation has reached an epoch of this 

 kind. It has become absolutely necessary for every one 

 engaged in the study or investigation of the science to make 

 himself acquainted with its present circumstances, and to 

 ascertain the probable direction of its future course. 



I propose, in this lecture, to give a brief summary of my 

 own views on this subject, and I would here express the 

 gratification which I feel in having an opportunity afforded 

 me of stating these views to the members and visitors of a 

 society which has for a long period been largely instrumental 

 in the development and propagation of organic science. 



Three distinct groups of subjects engage at present the 

 attention of physiologists : — 



1. The structure and actions of the living organism con- 



sidered as a chemico-physical system. 



2. The numerous forms in the series of organisms, embryo 



and adult, viewed as modifications of certain abstract 

 organic forms or ideal types, 

 vol, I. u 



