where it is able to perform the primitive functions of life. For weeks, months or even years, according to the class of the animal, it must be supported and protected by its parents. The human young receives milk from its mother's breast and protection in its mother's arms during its first year, after which it continues to receive nourishment, clothing and protection under the parental roof for a period varying from eighteen to twenty years, or even longer.

c. Support and Protection of Weaker Members of Society.—Young animals are supported and protected because they are unable to support and protect themselves. If they were not thus cared for the race would become extinct. Now, there are certain individuals, orphans for example, who have, through some accident, been deprived of their natural support and protection. If these weaker members of society, not yet able to support and protect themselves, were not provided for, they would perish and become thus lost to the race. From the time of primeval man to the present, these weaker individuals of society who have been deprived of their natural protectors, have been cared for by the stronger members of society and afforded such support and protection as they may need to make them independent. In a similar way the sick and defective members of society are cared for by the strong. Thus we see that the building and maintenance of orphanages, hospitals, asylums and "homes," are activities that belong clearly to the group of phyletic or altruistic activities.

2. SOME GENERAL PRINCIPLES OF BIOLOGY.

Sacrifice and Compensation in Egoistic Activities.

The thoughtful student is very likely to ask—Why does man till the fields? Why does man fell the forest trees? Why does he cultivate domestic animals? Why does he delve in the earth for minerals? These are all strenuous activities that require the outlay of time, talent and strength. We may say that they are sacrifices that he makes and, apparently, willingly. We have only to study the problem more closely to see that he tills the fields and cultivates his domestic animals for food; that he fells the forest trees to make for himself shelter; that he cultivates certain plants and animals to procure for himself clothing; that he delves in the earth to bring out mineral products to use in the various industries that supply various elements of his livelihood. It becomes manifest then that the egoistic activities of an organism represent sacrifice followed by compensation. The individual sacrifices in order that he may reap his reward or receive his compensation. It may be stated as a general biological truth that, nature demands sacrifice or work on the part of all living organisms; and, under normal conditions, metes out a compensation commensurate with the sacrifice made.

Sacrifice and Compensation in the Phyletic Activities.

a. Lower Organisms.—As an example of a lower organism we may take the amoeba. If one watches an amoeba under the microscope he may see it move about the field, creeping along the surface of the glass plate; throwing out a pseudopodium here; invaginating a mouth or stomach there; taking in and digesting minute plant organisms; transporting itself across the field of the microscope through the aid of improvised locomotory organs. All these activities are egoistic. The amoeba is putting forth effort to gain its sustenance; it is sacrificing energy to receive compensation in the form of support. If we continue to watch this minute organism we will find that sooner or later it goes into a resting stage which does not last long before we can observe important internal changes making themselves manifest first at the nucleus, which slowly divides into two equal portions that separate, each carrying with it about half of the protoplasm of the parent organism. As these two young amoebae lie side by side under the microscope the thoughtful student will inquire—what has become of the parent organism? Whereas at first there was one mature amoeba, now we have before us two young amoebae of the next succeeding generation. The parent organism has sacrificed its substance and its individuality absolutely and completely for the next generation.

Plate I
Reproduction in the Amoeba.

It may be said in general that reproduction always involves a division of the parent organism. In the case of the amoeba the division is into two equal portions. In the case of some of the lower plants and animals the substance of the parent organism is divided into many equal minute spores or eggs, each of which develops a new organism.

b. Higher Organisms.—These also suffer a division of their body protoplasm. However, instead of dividing into two or more equal parts and merging their individuality immediately into the next generation, the higher organisms divide off a very small portion of their protoplasm to make an egg or seed while the parent organism lives on to produce eggs or seeds on subsequent occasions.

While the parental sacrifice in eggs or spermatozoa is minute and inconsiderable in the higher animals, the sacrifices subsequent to this initial division are incalculably greater in higher animals than in the lower organisms. We can cite no better example than the human subject. The human ovum, divided off from the maternal organism, is a minute globule of protoplasm, almost microscopic in size. The sacrifice of the mother in producing the ovum is inconsiderable, but the production of the ovum is simply the first step in the sacrifice which the maternal organism makes.

The fertilized ovum makes a lodgment on the inner surface of the uterus or womb and begins immediately to absorb its nourishment from the maternal organism. It soon develops a heart and blood vessels so related to the blood vessels of the mother that throughout its intra-uterine existence the mother's blood supplies the growing child all of the substance that is built up into bone, muscle, brain and glands, preparing the young child to come into the world a living, breathing, sentient organism. These draughts upon the vitality of the maternal organism are so great that they frequently result in a very sensible depletion of the mother's physical power, particularly manifest in the depletion of the blood.

During the period when the young child is developing within the body of the mother, she must make other sacrifices, viz., the withdrawal from society more closely within the four walls of her home where she busies herself many days in preparation of the wardrobe for the expected child. Then there are sacrifices incident to childbirth represented especially in the pain and travail of parturition. During the first year of the child's life in normal cases, it draws its nourishment from its mother's breast. This nourishment in turn is elaborated by the milk-secreting glands from the mother's blood—still further depleting her system. During its childhood and youth the mother prepares the food, clothing and shelter of her child at no small expense of her own time and strength. For years the mother holds herself ready to watch by the bedside of her child should he fall sick, and there is hardly a mother in the land who has not spent many nights in this vigil by the bed of her sick child.

We might turn now