The influence of alcohol and other anesthetics on developing embryos

In previous experiments I had found magnesium salts to induce peculiar defects in the eyes of fish embryos. When eggs are subjected to such solutions, a large percentage of the embryos present all degrees of the cyclopean defect, while other individuals develop a normal eye on one side of the head with its mate on the other side small and defective or entirely absent. This latter condition was termed Monophthalmicum asymmetricum to distinguish it from true median cyclopia.

It seemed probable that these defects were due to the anesthetic properties of the magnesium solutions and to test this supposition eggs have been treated with several other anesthetics; alcohol, chloroton, chloroform and magnesium again. All of these act particularly upon the developing central nervous system and sense organs. Other parts of the body are somewhat delayed in their rates of development but are normal in appearance.