R. W. GERARD 23 



formative process. It supplies the physico-chemical milieu determining 

 molecular changes, the electro-chcmico-mechanical held guiding cellular 

 changes, the neuro-chemico-mechanical influences modulating organ 

 development, the material and biotic stimuli that guide the maturation oi 

 the individual, and the coded and meaning-laden signs and symbols which 

 arc added to these in the course ot enculturating an individual into his 

 group. The stresses applied by the environment determine the direction of 

 development of the individual and the selection of the individual in the 

 group. It may deternnne the adaptations of the body, the behaviour of 

 the individual, the nornis of the culture, and, in general, the goals or values 

 that guide the course of future change of a system. 



Living thmgs are engaged in a continuous tracking operation, attempt- 

 ing to bring their existing state or their anticipated state into congruence 

 with a desu-ed state. At any instant in time, the system faces its universe, 

 from which it is separated by some kind of boundary, with a certain 

 patterned inhomogenity which is by then its enduring property. In the 

 course of interacting with its environment, u-reversible changes are 

 produced in the system and it reaches a new state, the new architecture 

 which it then offers for interaction with further environmental stimuli or 

 stresses. Any individual system, and all its sub-systems, thus brings a new 

 self to succeeding chunks of time. What the zygote brings we ordinarily 

 call heredity, the end-product of ancestral learning and selection. What 

 happens to the zygote we call individual experience, often divided further 

 into experiences /// iitero, which we call congenital, and those affecting the 

 separate organism, tirst the infant and then the adult. 



At each stage and at each level, the system or sub-system presents to the 

 environment a structure which has at least some aspects of a template, and 

 so can lead to the production of more or itself; and at least some aspects of 

 a programme or set of operation rules, so that the kinds of responses it 

 will make to certain situations are roughly indicated. The outcomes are 

 never identical and never foreseeably deterministic, because the tine 

 details of the particular template and programme, even in identical twins, 

 are not absolutely identical and, even more, because the environmental 

 conditions to which these are exposed are never even roughly identical. 

 Despite relative constancy in 'beings', therefore, outcomes are always 

 more variable, the exact one in each case depending on the particular, often 

 chance, details of the individual — environment interaction. Clearly, the 

 line between heredity and individual experience becomes vague indeed. A 

 gene array is a template and a programme; so is an engram. 



It is a duty of neurobiology to discover the action rules. (If the nervous 



