POISONS. 221 
bring on, not merely a single responsive spasm, as 
in the unpoisoned animal, but a whole series of 
successive spasms, which are often followed by a 
paroxysm of twitching convulsions. The condition 
of exalted reflex irritability is thus exceedingly 
well marked. Recovery in normal water at this 
stage is rapid, the motions being at first characterized 
by a want of co-ordination, which, however, soon 
passes off. 
5. Veratrium.—tIn Sarsia the first effect of this 
poison is to increase the number and potency of the 
contractions; but its later effect is just the con- 
verse, there being then prolonged periods of quies- 
cence, broken only by very short swimming bouts 
consisting of feeble contractions. The feebleness 
of the contractions gradually becomes more and 
more remarkable, until at last it is with great 
difficulty that they can be perceived at all; indeed, 
the progressive fading away of the contractions 
into absolute quiescence is so gradual that it is 
impossible to tell exactly when they cease. During 
the quiescent stage the animal is for the first time 
insensible both to tentacular and to direct stimula- 
tion of the contractile tissues. That the gradual 
dying out of the strength of the contractions is not 
altogether due to the progressive advance of central 
paralysis, would seem to be indicated by the fact 
that contractions in response to direct stimulation 
of the con'ractile tissues are no more powerful, at 
any given stage of the poisoning, than are either 
responses to tentacular stimulation or the spon- 
taneous contractions. Still, as we shall immediately 
