Just as there are two sorts of mice in our illustration, white and black, there are two types cf sexual folks, males and girls. It has been revealed in various conditions by new discoveries that the sexual intercourse of the embryo is by now established in the fertilized egg, and in other scenarios it appears to be identified even in advance of fertilization, but this need to have not suggest that there are male and female eggs, and male and female spermatozoa. One circumstance of specific difficulty should not go unnoticed since Castle has built an intriguing recommendation that appears to distinct up a trouble, provided the details on which the conclusion rests are confirmed. In a case like that of the silk-worm, where by a graded sequence exists, the measurement of the egg appears to be the determining aspect in respect to which sexual intercourse develops, not that the feminine sexual intercourse-components are discovered only in the substantial eggs, and the male features in the smaller eggs. In bees the addition of the chromatin of the spermatozoon seems as a rule to decide that the egg presents increase to a woman. If they are fertilized by female spermatozoa they will give increase to ladies, and, on the speculation, only woman spermatozoa can enter male eggs.
