Fertilisation

Fertilisation is that essential process of sexual reproduction in which the male element (spermatozoid, antherozoid, pollen-tube) comes into contact and more or less complete union with the female element or ovum (see REPRODUCTION), and through which the subsequent division and differentiation of the ovum becomes effectively possible (see EMBRYOLOGY). The term is, however, often more loosely employed to denote those preliminary processes by which the male fertilising element is brought into conditions for beginning fertilisation proper. Hence, while the zoologist speaks commonly of the fertilisation of the ovum, but of the fecundation of the female animal, the botanist, in speaking of the fertilisation of the flower, is referring to the wind or insect agencies by which the pollen is brought to the stigma, and of the details of floral structure and mechanism adapted to these, the term fecundation thus being more frequently applied to the subsequent and essential process. See FLOWERS.