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Updated: May 27, 2025
After a time each individual absorbs its flagella, the colony is broken up, the different individuals settle to the bottom, and each gives rise by division to a new colony. This group of cells may be considered as a colony or as an individual. Each term is defensible. Volvox is also a spheroidal organism, composed often of a very large number of flagellated cells.
I am surprised. He is the only one who finds fault with me. He is a Dissenter, you know. The 'Monitor' is the Dissenters' organ, but my husband has been so useful to them in municipal affairs that they would not venture to run my book down; they feel obliged to tell the truth about me. Still Volvox betrays himself.
One of the most remarkable of these, the volvox globator, has exactly the form of the germ which, after passing through a long foetal progress, becomes a complete mammifer, an animal of the highest class. It has even been found that both are alike provided with those cilia, which, producing a revolving motion, or its appearance, is partly the cause of the name given to this animalcule.
Thus a hollow, or fluid-filled, little sphere, like the Volvox, is the natural connecting-link between the microbe and the many-celled body, and may be taken to represent the first important stage in its development. The next important stage is also very clearly exhibited in nature, and is more or less clearly reproduced in the embryonic development of all animals.
It was I who destroyed Ehrenberg's theory that the Volvox globator was an animal, and proved that his "monads" with stomachs and eyes were merely phases of the formation of a vegetable cell, and were, when they reached their mature state, incapable of the act of conjugation, or any true generative act, without which no organism rising to any stage of life higher than vegetable can be said to be complete.
Comparing this animal with an association like Volvox, we discover the same differentiation into immortal germ-elements and mortal cells, concerned respectively with the Hydra's racial existence and with its individual life; but far-reaching changes have come about in the biological relationships of the second class of cells.
In volvox they are entirely subservient to, and exist for, the reproductive cells, and die when they have completed their service of these. The body is here only a vehicle for ova. Furthermore, in volvox there has arisen such an interdependence of cells that we can no longer speak of it as a colony.
A clear social relation is thus established; and the reflex conduct of the units of a Volvox colony can be justly denoted altruistic, even though in this case, as before, there can be no conscious recognition of the reasons why mutual interests are best served by what is actually done.
But the other cells, which have been all the time nourishing these, seem now to lack nutriment, strength, or vitality to give rise to a new colony. They die. We find thus in volvox division of labor and corresponding difference of structure or differentiation; certain cells retain the power of fusing with other corresponding cells, and thus of rejuvenescence and of giving rise to a new organism.
In this animal there evidently appears a power of reproduction without any maternal apparatus for the purpose of supplying nutriment and oxygenation to the embryon, as it remains attached to its father till its maturity. The volvox globator, which is a transparent animal, is said by Linnæus to bear within it sons and grand-sons to the fifth generation.
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