_Motives for the Conduct of the Different Classes._--History and present fact are again enlightening in that they reveal the chief motive that determines the rapidity of the increase of the population. When children become self-supporting from an early age, the burden resting on the father when he has a comparatively small number of them is as large as it ever will be. If they can earn all they cost when they reach the age of ten, the maintenance of the children will cost as much when the oldest child has reached that age as it will cost at any later time. Even though one were added to the family every year or two, one would graduate from the position of dependence every year or two, and the number constantly on the father's hands for support would probably not exceed five or six, however large the total number might become. The large number of children in families of early New England and the large number of them in French Canadian families at a recent date were due to the fact that land was abundant, expenses were small, and a boy of ten years working on the land could put into the family store as much as his maintenance took out of it. The food problem was not grave in those primitive places and times, and neither were the problems of clothing, housing, and educating. It is in this last item that the key to a change of the condition lay, for the time came when more educating was required, when the burden of maintaining children continued longer, and a condition of self-support was reached at no such early date as it had been in rural colonies. _The Effect of Endowing Children with Education and with Property._--When children need to be thoroughly educated, the burden of maintaining a family of course increases. An unduly large family means the lowering of the present standard of living for all and a lowering of the future standard for the children. With most workmen it is not possible either to endow many children with property or to educate them in an elaborate way. The fear, therefore, of losing present comforts for the family as a whole and the fear of losing caste by seeing the family drop, at a later date, into a lower social class, are arguments against large families.