570 PROCEEI/IXGS OF SECTION I. 



sort of body, with certain limitations as to colour, might be pro- 

 duced by any or every sort of j^arents, and might be endowed with 

 any sort of mental qualities, except that mind and body w^ere 

 alike wholly evil — conceived in sin and brought forth in iniquity. 

 Since every organism is the resultant or product of two sets of 

 forces, viz., intrinsic or inherent, i.e., its inherited conditions or 

 heredity, and extrinsic or outward, i.e., its environmental condi- 

 tions or environment, it is necessary to define the terms heredity 

 and environment. 



What is heredity 1 Heredity is the influence of parents on off- 

 spring; in other words, it is the tendency manifested by an 

 organism to develop in the likeness of its progenitor. Heredity 

 simply means that the offspring tends to resemble the parent ; that 

 like tends to beget like ; man like m.an, dog like dog, apple like 

 apple. This, of course, nobody denies. It is a statement founded 

 on extensive observation, and, therefore, strictly scientific. 



What is environment ? Environment is the aggregate or sum 

 total of surrounding conditions in which a man, other animal, or 

 organism develops — it is the totality of all the outward conditions 

 and forces to which an organism is subjected, as distinguished from 

 its ovv^n inlierent properties or forces. That environment does 

 exist, and does influence every organism, is another unassailable 

 scientific truth. 



So far, all is clear. But when we ask. What part is due to 

 heredity, and what to environment, our difficulties begin. For 

 this is, in fact, another mode of stating the problem of variation. 

 If heredity means that like begets like, variation means that like 

 begets unlike ; and the question arises. Is all variatioii due to 

 environment ; if not, how much of the variation or unlikeness is 

 due to heredity, and how much to environment ? 



Darv/in held that every new animal and vegetable form is 

 developed fi'om a previously existing form b}^ variations that prove 

 useful to it in competition with " fellows, foes, and physical 

 forces," either by way of combat, or procurement of food, or self- 

 protection, or in some otlier way, and that are transmitted to, and 

 rendered permanent in, some or all of the offspring. He believed 

 tliat such variations, term.ed "individual variations," occur fre- 

 quently, are widely spread, are usually small, and that the new 

 forms originate by a gradual process from the slow elimination of 

 the old forms and the slow "fixing" of the new. Incidentally, 

 I may point out that there is evidence, from observations by 

 De Vries and others, that new forms may originate by a leaj), 

 depending on the fixing of large "single variations," "sports," 

 "discontinuous variations," or "mutations"; a fact of which 

 Darwin was cognisant, but to which, after some studj', he attached 

 very small importance in his scheme of evolution. 



