148 JELLY-FISH, STAR-FISH, AND SEA-URCHINS. 
These observations may be taken as samples of 
others which it would be unnecessary to quote, as 
it will be seen from the above that there is no pre- 
cise relation between the number of the pulsations 
and the duration of the pauses. Nevertheless, thai 
there is a general relation may be seen from some 
cases in which unusually prolonged pauses occur. 
-The following instance will serve to show this :— 
Sarsia (another specimen). 
Number of pulsations. Seconds of rest. 
38 30 
22 35 
49 40 
30 45 
46 20 
2 15 
24 880 
112 20 
45 185 
894 30 
6 45 
4 140 
2 185 
30 240 
200 60 
In this case, the relation between the long pause of 
380 seconds and the subsequent prolonged swim- 
ming bout of 112 pulsations is obvious; also, as 
the latter was then followed by a short pause of 
twenty seconds and another comparatively short 
bout of forty-five pulsations, the refreshing influence 
of the previous 380 seconds rest may be supposed 
to have been not quite neutralized by the exhausting 
effect of the foregoing 112 pulsations. At any rate, 
looking to the general nature of the previous pro- 
portions (viz. in their sum 34#), it is certain that 
380 leaves a large preponderance in favour of nutri- 
