select the ingredients from its environment that are essential to its 

 growth and development, and with that subtle chemistry that is 

 everywhere at work in the organic world, will produce its kind. 

 This law holds good in the animal kingdom as well as amogg 

 plants. If a number of animals of different species are taken 

 in their infancy and subjected as nearly as possible to the same 

 influences, it will be observed that each will develop into a distinct 

 type, differing in almost every respect from the others. The 

 observance of this law convinces us that the principle of each plant 

 or animal, which enables it to preserve the peculiarities of its 

 species, is an inherent principle which is part of its nature, in- 

 herited from its ancestors, and by it given to its offspring. Thus 

 we have a universal law which enables each individual to transmit 

 to its offspring certain essentials that are common to all the 

 individuals of its species. Yet there are differences or peculiarities 

 that distinguish each member of a species from all others. Now, 

 how are we to account for these individual differences ? This is 

 the province of heredity and environment. It is a well-known 

 fact that no two persons are identical. It is also a self-evident 

 fact that identical causes will produce identical* effects, and that 

 unequal causes will produce unequal effects. We know, too, that 

 the latent powers, the latent possibilities that are concealed in each 

 embryonic life, are variable quantities. We also know for a certainty 

 that the influences which surround these individual lives — the en 

 vironment — for moulding and shaping into a fixed state the plastic, 

 latent, inherited predispositions are never identical. Therefore, in 

 the question with which we have to deal, we have not only two 

 unknown quantities, but two variable unknown quantities that are 

 never the same or alike in two individuals — heredity and environ- 

 ment. Now, since there are no two persons with identical predis- 

 positions, what will be the result if we expose them to equal 

 influences? Or the reverse : If we expose a number of perso.is of 

 unequal predispositions to equal influences, the result must be 

 unequal. If the environment is an uncongenial one, the person 

 with an inheritance most approaching normal will possess the 

 greatest power of resistance, and consequently will be the last to 

 yield to malignant influences. The inverse of this is also true. 

 Suppose, for instance, that all men were born equal, how long 

 would they remain so if exposed to unequal influences? Dr. 

 Weisman says : " We cannot, by excessive feeding, make a giant 

 out of a dwarf, nor convert the brain of a fool into that of a Leib- 

 nitz, or a Knnt, by means of much thinking." Spencer says : 

 " There is no political alchemy by which you can get golden con- 

 duct out of leaden instincts. The inherited differences of individuals 

 are known as individual predispositions. These predispositions 

 render the individual more or less susceptible tu exiernal influences. 

 Heredity is therefore that law of nature whereby parents trans- 

 mit to their offspring certain variable powers termed predispositions, 

 which render their offspring more or less suueptible to their environ- 



