CHAPTER II

THE BASIS OF THE POPULATION PROBLEM: (1) THE QUANTITATIVE ASPECT 37

(1) The ancestors of man were once subject to the conditions prevailing among species in a state of nature. These conditions are studied. (2) Reproduction, the necessity for which can be explained, (3) always consists in the fusion of two gametes, but (4) is accomplished by different methods. (5) Whatever the method, most ripe ova are fertilized, though among lower forms failures may not be infrequent. A reference to the nature of (6) reflex action, (7) instinct, (8) intelligence, and (9) reason shows that, (10) whatever the stage of mental evolution reached among species in a state of nature, reproduction is essentially ‘mechanical’. (11) The vast number of ova (12) is only partially called for by the fact that a certain proportion only is fertilized. The vast number is necessary because (13) owing to the interdependence of all species a large proportion of the young of (14) both animals (15) and plants perish before maturity (16) and is determined by the sum of the dangers to which the young are exposed.