ON THE CORRELATION BETWEEN GROWTH 
AND FOOD SUPPLY IN STARFISH. 
A. D. MEAD. 
In the higher vertebrates there is a pretty constant relation 
between the age of an individual and its size, at least up to 
the time when the full stature is reached. This relation is 
expressed in carefully constructed curves of growth, and it may 
be inferred from common observation. The healthy individual 
must be able, during its early life, not only to hold its own in 
respect to size, but also to grow ; the time between meals must 
be comparatively short, and the nourishment assimilated must 
be more than sufficient merely to replenish waste tissue. 
Minot has shown for guinea pigs that even “any irregularity 
in the growth of an individual tends to be followed by an oppo- 
site compensating irregularity.” “If an individual grows for 
a period exceedingly fast, there immediately follows a period of 
slower growth; and, vice versa, those that remain behind for a 
time, if they remain in good health, make up the loss (at least 
in great part if not always completely) soon after." ‘Each 
individual appears to be striving to reach a particular size ” — 
a particular size, we might add, not only for the adult age but 
for any particular previous age. 
The normal rate of growth of marine invertebrates seems 
not to have received much attention, and were one to inquire 
among longshoremen or seaside naturalists how old an eight- 
inch lobster is, or how long it takes a starfish to grow to a cer- 
tain size or to become sexually mature, he would meet with an 
interesting variety of opinions and receive little satisfactory 
‘ information. 
Several years ago Alexander Agassiz made an estimate of the 
rate of growth in starfishes, which was based upon the supposi- 
tion that a close relation does obtain between size and age in 
these animals as well as in vertebrates. The method which he 
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