54 



E. I. WERBER. 



this toxic substance has upon developing eggs in the first and 

 second or in the third and fourth divisions. In the former case 

 anterior hemiembryos, dwarf embryos with deformities of the 

 eyes or of the otic vesicle, and malformations of the most extreme 

 kind were predominant, while in the latter deformities of the 

 eye such as cyclopia and monophthalmia, etc., were mostly 

 observed. In either case, however, there were very few embryos 

 in which only the nervous system was affected. In most of the 

 deformed embryos all organ systems were more or less involved 

 in the malformation. 



Similar results were obtained with acetone in sea water, varying 

 in concentration from 20-50 c.c. of a molecular solution in 50 c.c. 

 of sea water. In this mixture the eggs remained from 24-72 

 hours from the eight-cell or sixteen-cell stage. In every case 

 great numbers^ of monsters similar to those already mentioned 

 were produced. 



The monstrosities in both series of experiments with butyric 

 acid and acetone being essentially alike it will not be necessary 

 to describe separately the deformities produced by each. 



Cyclopia and asymmetric monophthalmia were found to occur 

 rather abundantly. There were also some cases of asymmetric 

 monopththalmia in which an open orbit was found on the side 

 lacking the eye. It is of some interest to note in this connection 

 that the eyeless orbit in such cases is usually closed on the outside 

 by periorbital tissues. The anatomy of the head of such embryos 

 may probably reveal some interesting conditions. Other cases 

 of asymmetric monophthalmia were found in which an apparently 

 free eye had developed on the yolk-sac at a considerable distance 

 from the embryo. Probably the most striking of the results 

 obtained in this investigation were some eggs in which nothing 

 could be observed but an eye. In only one case this eye seemed 

 to be perfectly developed, while the other solitary eyes had 

 " coloboma "-defects, the fissure of the chorioid still being 

 patent. Only a few (five or six) of these malformations are 

 recorded, but in spite of their rare occurrence they are very sig- 

 nificant from the standpoint of experimental embryology. At the 



1 No attempt was made to ascertain the percentage of the deformities found in 

 these experiments, this part of the work being deferred to later investigation. 



