ME. Gr. J. BOMANES ON THE LOCOMOTOE SYSTEM OF MEDTJSiE. 
669 
previous clay. The following is a sample of several such observations, all yielding the 
same general result. 
Segment 4. 
Segment 4. 
Segment f A. 
Segment -§■ B. 
j Number of 
i pulsations. 
Seconds of 
rest. 
No motion during the 
hour of observation. 
Continued persistently to 
contract with a nearly 
perfect rhythm of 78 in 
the 5 minutes during the 
hour of observation. 
Ehythm tolerably perfect at 
78 in the 5 minutes ; but 
this was occasionally in- 
terrupted by long pauses 
of 4 or 5 minutes duration. 
12 
1 3 
44 
j 12 
120 
10 
20 
130 
20 
73 
5 minutes. 
Average rate 
14| per minute. 
No motion. 
Continuous rhythm at the Interrupted rhythm at the 
rate of 15-| per minute. rate of 15A per minute. 
I how transferred all the segments to fresh sea-water, with the following results : — 
Rhythm during first quarter of an hour immediately after transference, in 
five minutes’ intervals. 
1 
Time. 
Segment 4- 
Segment 4- 
Segment 4 A. 
Segment § B. 
First 5 minutes .... 
Second 5 minutes . . 
Third 5 minutes .... 
139 (irregular). 
0 
100 (regular). 
0 
0 
39 (irregular). 
83 (regular). 
68 
70 
20 (irregular). 
75 (regular). 
69 
Rhythm 2 hours after transference (5 minutes’ intervals). 
Segment 
Segment 4- 
Segment § A. 
Segment g B. 
82 (regular). 
77 (regular). 
70 (regular). 
62 (regular). 
Rhythm next day (5 minutes’ intervals). 
Segment 4- 
Segment 4. 
Segment 4 A. 
Segment 4 B. 
68 
55 
17 
Dead. 
1 
Next day all the segments were dead except the largest one, in which a single litho- 
cyst still continued to discharge at the rate of 24 in five minutes. 
Now, with regard to these Tables it is to be observed that during the first day the 
prepotent lithocyst in the eighth-part Segment A maintained an undoubted supremacy 
over all the others, and that the same is true of the comparatively potent lithocysts in 
the quadrant. (This is not the case with Segment B; probably the degree of pre- 
potency of the lithocyst in this case was not sufficient to counteract the antagonistic 
5 b 2 
