Gland-Cells of Internal Secretion in Spinal Cord of Skates. 21 
SECOND SERIES OF SKATES. 
Skate 117: 
Skate 118: 
Skate 113: 
Skate 114: 
Skate 116: 
Skate 116: 
Skate 157: 
Stimulated for 2 minutes, fixed immediately. 
Stimulated for 2 minutes, fixed immediately. 
Stimulated for 5 minutes, fixed immediately. 
Stimulated for 5 minutes, fixed immediately. 
Stimulated for 10 minutes, fixed immediately. 
Stimulated for 10 minutes, fixed immediately. 
Stimulated for 10 minutes, fixed immediately. 
Eleven other skates were taken as normal control animals and exam- 
ined as to the amount of granular material present. 
It appeared from superficial examination of the results of the experi- 
ments described above that electrical stimulation of the spinal cord 
caused an increase in the amount of granular material. Since, how- 
ever, the amount of granular material present in any section varied 
greatly even in the same animal, it became desirable to adopt some 
method by which the average amount could be determined. The fol- 
lowing method was used: A granule of a certain size was taken as a 
unit, and an estimation of the amount of granular material in terms of 
this unit was made in the case of each section. The results were aver- 
aged and the number of unit granules per section was computed. 
From the 17 stimulated skates of both series of experiments an 
average of 17 unit granules per section 
mal control animals showed an aver- 
age of 10.7 unit granules. A definite 
increase in granular material, there- 
fore, is correlated with stimulation of 
the spinal cord with electricity. 
Text-figure 2 gives a graphical repre- 
sentation of the results obtained from 
the stimulation of the skates of the 
first series. The abscissee represent 
the time of stimulation in minutes, the 
ordinates the amount of granular ma- 
terial in terms of unit granules. In 
skates stimulated for 2 minutes the 
average section contained about 19.4 
unit granules. In skates stimulated 
for 5 minutes the average section contained 19.8 unit granules. 
was obtained. The 12 nor- 
w 
to) 
Unit granules 
Nn 
oO 
0 2 5 20 
10 
Time in minutes 
TEXT-FIGURE 2.—A curve showing 
relative amounts of granular secretion 
present in the spinal cord after stimu- 
lation with electricity for various 
lengths of time. The abscisse repre- 
sent the time of stimulation in min- 
utes, the ordinates the number of unit 
granules per section. This curve is 
based upon 12 normal skates and 10 
stimulated ones. 
In 
skates stimulated for 10 minutes the average section contained 24.4 
unit granules. In those stimulated for 20 minutes the average section 
contained 27.1 unit granules. Increased granular secretion is here cor- 
related also with the length of the time of stimulation. 
