370 Charles R. Stockard. 
alcoholic specimens ever develop sufficiently to hatch and swim 
about as do the Mg embryos. An explanation for this may 
be that Mg exerts an influence to inhibit dynamic processes, such 
as the out-pushing of the optie vesicles, while alcohol acts more 
especially on the nervous tissues. Mayer (1908) has shown that 
Mg inhibits muscular contractility without affecting in any way 
the nervous impulse or nervous rhythm. 
The eye defects, it must be remembered, have only been ob- 
tained in solutions of one or another anesthetic; the many other 
salt and sugar solutions which have been experimented with dur- 
ing four years (06 and ’07) have failed entirely to produce similar 
results. 
The most important outcome of these experiments has been to 
prove conclusively that many monsters which occur in nature 
may be artificially produced by changing the environment of the 
normally developing eggs. The present experiments will demon- 
strate that this may be done even after development has pro- 
ceeded for some time. ‘These anomalous structures being the 
results of external influences and not germinal variations are to 
some extent within scientific control. A promising field is thus 
opened in the devising of means to control or regulate the devel- 
opment of the embryo and possibly to obviate certain monstrous 
conditions at least, Such possibilities were of course beyond our 
reach if defective germ cells were actually the cause of these mon- 
sters. 
Mall (08) has brought forward evidence to show that im- 
proper placentation or unfavorable developmental environment 
is responsible for most human monstrosities, many of which are 
aborted before reaching term. There is evidently much need of 
investigation aiming toward the control and regulation of the 
developmental environment of mammals. 
METHOD AND MATERIAL 
The eggs of the fish, Fundulus heteroclitus, were used in all of 
the experiments. The method of treatment varies somewhat 
for the different solutions employed, so that it is best to describe 
each separately. 
