488 
Da\id H. DoUey 
state of activity. The first twenty five of the animals were those 
obtained in October when the work was started. The rest were obtained 
in the Spring at different times from the first thaw to the middle of May. 
Experimental Methods. 
Only the two methods which proved most effective in exciting the 
animals to continuous or briefly interrupted acthdty and which furnished 
the material for detailed study need be discussed. Various other schemes 
were employed in the attempt to force the anünals to normal boddy 
activity. These were discarded as it soon became apparent that, on 
account of the slow reaction and endurance of this primitive nervous 
System, which will be brought out later, they failed to produce measmable 
or even appreciable results in comparison with the variations in undisturbed 
animals. Days rather than hours must be the duration of such experiments 
and hence, of necessity, only such excitants as work automatically are 
applicable. 
Of these two methods, the first employed was electrical Stimulation. 
Into a large porcelain dish, suffidently fUled with water to submerge 
the animal, a glass plate was introduced so as to rest upon the bottom 
and the edge of the dish, thus making an inclined plane. The animal, 
placed upon his back, was held in position upon this plane by means of 
Strings tied to his fore claws and running out over the edges of the glass 
plate. The tightness of the strings was easily adjusted to allow some 
freedom of movement without permitting the animal to turn over or 
to reverse his position. Next the animal was introduced into the secondary 
Circuit of an induction coil as foUows: one wire from the coil was tied to 
an antenna, the other was attached to an ii'on weight placed in the bottom 
of the porcelain dish. The water completed the circuit. Into the primary 
Circuit of the induction coil was introduced an electrical time clock acti- 
vated by independent batteries which permitted the animal to be shocked 
at any desired interval. Various intervals between successive shocks 
were tried but finally two seconds was adopted as the most suitable. 
The feature of this group of experiments is then that at definite short 
intervals the animals were irritated by the passage of an electric current 
through their bodies in response to which there was a visible contraction 
of the whole body musculature. At the Start, the movements were con- 
vulsive in character and practicaUy continuous. These lasted for a vary- 
ing time, usually from one fourth to one half an hour. Gradually they 
would subside and the only response would come with the making of the 
