Human history, being a continuation of vertebrate history, is full of similar instances. The invention of the stock company, for example, furnished a certain relative freedom to hundreds, a certain amount of leisure to think and play, and independence to travel and record, and immunity from a daily routine and drudgery. In turn, it bore fruit in miseries and horrors multiplied for millions, like those of the child lacemakers of Mid-Victorian England, who were dragged from their beds at two or three o'clock in the morning to work until ten or eleven at night in the services of a stock company. A corporation is said to have no soul. The struggle for freedom of every living thing has no conscience. Throughout the living world, from ameba to man, parasitism and slavery together with their by-products, physical and spiritual degeneracy, appear as the after effects of the more vital individual's efforts to remain alive and free. The origins of slavery may be seen in the parasitisms of the infectious diseases which kill man. The change from parasitism to slavery was an inevitable step of creative intelligence. In the transition evolution made one of those breaks which it indulges in periodically as its mode of progress. The natural effect of slavery has been a selection of two sorts of individuals along the lines of the survival of the adapted. It has tended to perpetuate in the breed the qualities of the strong which would make them stronger, and certain qualities in the weak which would increase their weakness. For parasitism and likewise slavery infallibly entail the degradation of certain structures and an overgrowth of others by the law of use and disuse. The type of organ which would function normally, were not its possessor parasitic in that function, invariably degenerates or disappears. Parasitic insects lose their wings. An entire anatomical system may even be lost. So the tapeworm, which feeds upon the digested food present in the intestines of its host, has no alimentary canal of its own because it needs none. On the other hand, the organs of attack and combat grow by a constant use into the most remarkable of efficient weapons.