I] CHEMICAL EMBRYOLOGY 9 



animal bodies as machines impelled by certain forces and perform- 

 ing an amount of work which can be measured and expressed 

 in terms of the ordinary forces of nature. The final object of 

 physiology is to deduce the facts of morphology on the one hand 

 and those of oecology on the other hand from the laws of the mole- 

 cular forces of matter". It may be regarded as very noteworthy 

 that Huxley here puts morphology as secondary to physiology and 

 as it were derivable from it; he does not place morphology and 

 physiology on two high places, "neither afore or after other", as 

 has so often been done, but he plainly states his view that the 

 anatomical aspect of animals, their external and internal forms, could 

 be deduced from the interplay of physico-chemical forces within 

 them, if we only knew enough about those forces. This is the idea 

 of the primacy of function. It seems always to have two meanings, 

 firstly, the Epicurean-Lucretian one which Huxley adopts here and 

 Roux so brilliantly developed, in which shape is regarded as the 

 outward and visible sign of the properties of matter itself, and, 

 secondly, the Aristotelian one emphasised by J. B. de Lamarck's 

 writings in the eighteenth century, and in our time by E. S. Russell's 

 great work Form and Function, in which psychical factors are intro- 

 duced as the essential elements in the ultimate analysis of shape. In 

 both these interpretations, function has the priority over form, but 

 the meaning of function is the point of difference. Some biologists, 

 however, seem to think that physiology and morphology are cate- 

 gorical, and the latter is emphatically not reducible to or derivable 

 from the former. The two spheres of study represent, for them, 

 correlative and immiscible disciplines, morphology aiming ultimately 

 at solid geometry, physiology at causation, and "rerum cognoscere 

 causas" is not the basic desire of the scientific mind. They object 

 to the view which regards "the ovum as a kind of chemical device 

 wound up and ready to go off on receipt of a stimulus, the task of 

 the causal morphologist being to disentangle the complex of events 

 which constitute the unwinding process" (Woodger), complaining 

 that in this view no account is taken of the past history of the 

 race, which is left to genetics, again a causal discipHne. To some 

 extent these opinions spring from a conviction that the analytical 

 method is inapplicable to a living being because it is an organism, and 

 of that there is more to be said. But they also arise from a profound 

 unwillingness to subsume biology under physics and a desire to uphold 



