530 THE POPULAR SCIENCE MONTHLY. 



composition of the tissues and the humors through the absence of 

 one of their necessary constituents. The disturbance was not suf- 

 ficient to cause the larvae to perish or to stop the vital movement, 

 but that had been diverted and had resulted in a new configura- 

 tion 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 re- 

 move 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 con- 

 stitution. It is a point to which Darwin and his partisans of the 

 transformist school have not perhaps given sufiicient 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 exagger- 

 ation 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 ex- 

 ternal configuration that determine each animal or vegetable spe- 

 cies. The transformists show us with complete assurance verte- 

 brated 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 



