The same privilege is possessed by the predatory Hymenoptera, the Wasps, at least by those in whom the two sexes are of a different size and consequently require an amount of nourishment that is larger in the one case than in the other. The mother must know the sex of the egg which she is going to lay; she must be able to choose the sex of that egg so that each larva may obtain its proper portion of food. Generally speaking, when the sexes are of different sizes, every insect that collects food and prepares or selects a dwelling for its offspring must be able to choose the sex of the egg in order to satisfy without mistake the conditions imposed upon it. The question remains how this optional assessment of the sexes is effected. I know absolutely nothing about it. If I should ever learn anything about this delicate point, I shall owe it to some happy chance for which I must wait, or rather watch, patiently. Towards the end of my investigations, I heard of a German theory which relates to the Hive-bee and comes from Dzierzon, the apiarist. (Johann Dzierzon, author of "Theorie und Praxis des neuen Bienenfreundes."--Translator's Note.) If I understand it aright, according to the very incomplete documents which I have before me, the egg, as it issues from the ovary, is said already to possess a sex, which is always the same; it is originally male; and it becomes female by fertilization. The males are supposed to proceed from non-fertilized eggs, the females from fertilized eggs. The Queen-bee would thus lay female eggs or male eggs according as she fertilized them or not while they were passing into her oviduct. Coming from Germany, this theory cannot but inspire me with profound distrust. As it has been given acceptance, with rash precipitancy, in standard works, I will overcome my reluctance to devoting my attention to Teutonic ideas and will submit it not to the test of argument, which can always be met by an opposite argument, but to the unanswerable test of facts. For this optional fertilization, determining the sex, the mother's organism requires a seminal reservoir which distils its drop of sperm upon the egg contained in the oviduct and thus gives it a feminine character, or else leaves it its original character, the male character, by refusing it that baptism. This reservoir exists in the Hive-bee. Do we find a similar organ in the other Hymenoptera, whether honey-gatherers or hunters? The anatomical treatises are either silent on this point or, without further enquiry, apply to the order as a whole the data provided by the Hive-bee, however much she differs from the mass of Hymenoptera owing to her social habits, her sterile workers and especially her tremendous fertility, extending over so long a period.