710 
ZOOLOGY: L. R. GARY 
When the sense-organs were removed from one half disk in less than 
24 hours regeneration occurs just as if they had been removed at the 
time of the first operation. After about 26 hours, however, the removal 
of the sense-organs from one of the half disks had no apparent influence 
on the rate of regeneration, which was the same from both halves of 
any disk. 
Influence of marginal sense-organs on loss of weight in starving. — 
Mayer^ found that when Cassiopea was starved in sea water from 
which all food organisms had been removed by careful filtration, the 
loss of weight could be expressed mathematically by the formula y = 
W {l—aY, in which W = the original weight, x the number of days 
of starvation and a a constant, the 'coefficient of negative metabolism/ 
The value of a in the equation above differs in experiments involving 
varying conditions as regards light and darkness, presence or absence 
of regeneration, etc., but in all cases the formula gives a very close 
approximation to the observed loss of weight. 
In my experiments the two halves of a series of disks were compared 
after they had been subjected to operations which made possible the 
comparison of the halves of the disks upon one of which the sense- 
organs remained, while these were removed from the other half disk 
(active and inactive series); second, the comparison of half disks on 
one of which the sense-organs remained, while the other, from which 
all sense-organs were removed, had its muscles activated by a circuit 
wave of contraction maintained in an endless labyrinth of subumbrella 
tissue (active and activated series); third, half disks from which all 
sense-organs were removed, while one of them was activated by a cir- 
cuit wave of contraction (activated and inactive series). 
TABLE 2 
Loss of weight in active 
Loss of weight in active 
Loss of weight of activated 
and inactive 
half disks 
and activated half disks 
and inactive half disks 
Days after 
»peratiou 
Weight of 
half with 
sense-organs 
Weight of 
halt without 
S. 0. 
Weight of 
half with 
sense-organs 
Weight of 
activated 
half 
Weight of 
activated 
half 
Weight of 
half without 
S. 0. 
0 
100.00 
100.00 
100.00 
100.00 
100.00 
100.00 
1 
75.34 
81.81 
76.29 
79.41 
79.47 
81.97 
2 
66.72 
71.27 
67.18 
70.58 
70.63 
71.84 
3 
58.54 
64.09 
59.76 
61.99 
62.03 
63.91 
4 
55.27 
55.41 
55.88 
57.18 
57.21 
57.23 
In every instance the results follow closely those obtained when the 
regeneration was used as the standard of comparison. The results of 
the entire series of experiments are shown in the following tables, in 
which the original weight of each series of disks is taken as 100 so that 
the results read as percentages of the original weight. 
