Page:Popular Science Monthly Volume 45.djvu/548

530 composition of the tissues and the humors through the absence of one of their necessary constituents. The disturbance was not sufficient to cause the larvæ to perish or to stop the vital movement, but that had been diverted and had resulted in a new configuration of the living being. We have made a monster by a chemical process. No doubt a certain number of monstrosities besides those resulting from accidents that have occurred in the course of the development will eventually be attributed to a category of special changes like those which M. Chabry provoked.

A recent discovery has further cast a very striking light on that mysterious relation that connects the chemical constitution of beings with their external form. Aside from the serpents, only a few vertebrate animals are known that distill venom. On the other hand, notwithstanding the deep organic differences that remove the fishes from the reptiles, we find a few among them—the conger, the eel, and the sea eel—that have the appearance and almost the form characteristic of snakes. Prof. Mosso has lately shown that the blood of these fishes with the shape of a serpent is poisonous, even very poisonous. Half a thimbleful of eel's blood injected into a dog is enough to cause the animal to fall dead just as if it had been bitten by a rattlesnake. What is the connection between the presence of this poison in the blood of the eel and the shape of its body?

We may summarize in rigorously scientific language what we have just set forth by saying, with Chevreul and Charles Robin, that the form of living beings is a function of their molecular constitution. It is a point to which Darwin and his partisans of the transformist school have not perhaps given sufficient attention. Everybody now accepts these doctrines in their main features, but they have not taken into account, at least not fully, the factor of the influence of the medium. They have overlooked this chemical necessity which is imposed with every change of form or simply of color. We shall know, as M. Gautier has foreshadowed, the limits of the possible variations of an animal species when we learn how far it lends itself to the creation of new organic compounds. Even when there is nothing more than an exaggeration of a group of determined organs, a determining modification must be admitted in the chemistry of the individual. If media have been able to act, as everything indicates, it has been only by slow and progressive modification of the molecular constitution of the being, involving inevitably in its turn the changes of external configuration that determine each animal or vegetable species. The transformists show us with complete assurance vertebrated animals descended from some inferior animal, worm, or mollusk. Which? Here they cease to agree, and every one's preferences are suggested by this or that vague resemblance in