The most perfect and vigorous specimens of coniferous trees are of the female kind. In its highest and most luxuriant stage the larch bears only female blossoms, but so soon as its vigour is lost male flowers appear, after which death soon ensues. In _The Evolution of Sex_, by Geddes and Thomson, is the following: In phraseology which will presently become more intelligible and concrete, the males live at a loss, are more katabolic,—disruptive changes tending to preponderate in the sum of changes in their living matter or protoplasm. The females, on the other hand, live at a profit, are more anabolic,—constructive processes predominating in their life, whence indeed the capacity of bearing offspring.[33] [33] _The Evolution of Sex_, 1890, p. 26. Among the lower orders of animals, there appears an excess of males, and among the higher forms of life, man included, the fact that the male is the result of the cruder, less developed germ, has been clearly shown, not alone by the facts brought forward by Mr. Darwin, but by those enunciated by all reliable writers on this subject. As a result of the excessive eagerness in males, and the consequent expenditure of vital force among the lower orders of life to find the female and secure her favours, they are generally smaller in size, with a higher body temperature and shorter life. Among the higher orders, the human species, for instance, although man is larger than woman, he is still shorter lived, has less endurance, is more predisposed to organic diseases, and is more given to reversion to former types, facts which show that his greater size is not the result of higher development. It is noted that the liability to assume characters proper to lower orders belongs in a marked degree to males of all the higher species—man included. Doubtless man’s greater size (a modification which has been acquired through Sexual Selection) has been of considerable value to him in the struggle for existence to which he has been subjected, but the indications are already strong that after a certain stage of progress has been reached, even this modification of structure will prove useless, if not an actual hindrance to him. On mechanical principles, every increase of size requires more than a corresponding increase of strength and endurance to balance the activities and carry on the vital processes, yet such have been the conditions of man’s development, that his excess of strength does not compensate for his greater size and weight, while his powers of endurance fall below those of women.