CHAP, ii The Theory of Metamorphosis 83 



present even in the unicellular plant, just as Man is 

 potentially in the Amoeba ; and their gradual unfolding is 

 but a matter of time and the realisation of their inherent 

 tendency to complexity, much as we have in the spore or 

 the ovum, the potentialities which we see realised as it 

 grows into a plant. 



Vines laid special stress on this inherent tendency of 

 protoplasm. He asked why the course of development or 

 evolution has been in fairly uniform directions in large 

 groups of plants. The influence of environment appeared 

 to him insufficient, unless it were conceded that something 

 in the plant presented the material or tendency to work 

 upon. Something of the kind had been advanced much 

 earlier by Darwin in the Origin of Species, where he said, 

 ' In all cases there are two factors, the nature of the organ- 

 ism, which is the most important of the two, and the 

 nature of the conditions. The direct action of changed 

 conditions leads to definite or indefinite results. In the 

 latter case the organization seems to become plastic, and 

 we have much fluctuating variability. In the former case 

 the nature of the organism is such that it yields readily 

 when subjected to certain conditions, and all, or nearly all, 

 the individuals become modified in the same way '- 1 



Vines compared the inherent tendency to complexity of 

 development, which ultimately results in the revealing of 

 stem, root, and leaf as the plant's constituent members, 

 with the formation of crystals in the inorganic world. As 

 the assumption of a definite and constant crystalline form 

 is the expression of the special property of the substance, 

 so every living organism, whether plant or animal, possesses 

 a characteristic form which is the outcome of the properties 

 of its protoplasm. The latter differs from the former in 

 being unstable and subject to change. 



The morphologists of this school did not controvert the 

 1 Origin of Species, ed. 6, p. 106, 

 F 2 



