CHAIN OF CYCLOSALPA AFFINIS 413 
figs. 4 and 5 have been smoothed by averaging for every ninth 
point in order to make this curve more plain. The curves are 
not just the same for the two sides of Chain VI, the difference 
probably being due to a difference in the way in which the com- 
puted curve fits in the two cases. 
With what, if any, other biological phenomena in the species 
this newly discovered periodicity is connected we do not know. 
te zooids. ‘7 zoo/ds. ‘6 z00/d. 5 Z00/as '8 zoo/ds. \7 2ooids. 
15-1 l2-/8 9-24 125-29 J0-37 8-45. 
Chain Vil Right side. 
Flot of Oifferences. 
7zoo1ds.  :7 zo0ids. 16 200/ds. 'S zooids. ‘5 zovids.\ 5 200/ds\'|5 2o0ids.\ 4 200Kds. 
46-52. IS- FI. 1600-65, \66-79. ‘71-76. 77-8. 82-86. ‘87-90. 
Fig. 8 Plot of differences for chain VII, right side 
Inverted and possible groups indicated 
Of its existence however, there seems to be no doubt; and it is 
certainly interesting to recognize that we have here an instance, 
by no means uncommon in organic phenomena, of waves, so to 
speak, of one size riding upon those of another size. It is highly 
desirable to take these cases in hand with a view to finding their 
connection with other phenomena. 
