We have seen in a former chapter that what in the ordinary course of nature was "predestined" to become one individual nevertheless contained the possibility of becoming four or more if the environing conditions were made such as to bring about a separation of the cleavage blastomeres. Or a fish egg that contained the possibility of becoming a normal two-eyed form also contained the possibility of becoming a one-eyed form and could be made to do so by certain unusual modifications of the conditions under which it develops. However we must not be led so far by the plausibility of this comparison that we are misled, for the fact is that we are not creating anything new by these environmental upheavals, but are mainly altering features that already exist. Beyond doubt the nature of the material is of greater import in the specificity of the outcome than are the external forces brought to play on it. The only point I wish to make is that even what seem ordinarily to be predestined ends can be altered by environment, and that the probabilities are that certain features are relatively indifferent at their inception, the environmental factor adding the final touch of specificity. And our common experience in education would indicate that the same is true of mental conditions, including behavior. The actual appearance of a particular trait is not necessarily always a matter of an initial trend, but may be due merely to the fact that its development is possible under certain conditions of environment and that these conditions have prevailed in the given instance. And even where there is a specific bent it may be arrested through the awakening of a contrary impulse, or, on the other hand, its exercise may prevent the engendering of the opposite impulse. =Our Duty to Afford the Opportunity and Provide the Proper Stimuli for the Development of Good Traits.--=It is clearly our duty to see that the expression of good traits is made possible. We must throw a sheltering screen of social environment around the young individual which will fend off wrong forms of incitement and chances for harmful expression, and we must provide proper stimuli and afford opportunity for development of proper modes of expression. We must not forget that a normal instinct denied a legitimate outlet will not infrequently find an illegitimate one. Above all we must not forget the vital importance of establishing correct habits nor the possibility of even replacing undesirable ones by good ones. If training can redirect the machine-like behavior of as lowly a creature as the starfish into new courses, why should we be so willing as some of our genetists would seem to be to throw up our hands and admit failure in the case of man before we have even made a rational attempt to correct the evils in question? Even in lowly organisms we have seen that behavior is not only the result of an innate constitution but also of the degree and kind of stimulations to which it has been subjected.