NATURE OF EXCRETORY PROCESSES IN MARINE POLYZOA. 147 
serve that the walls of the alimentary canals took up any of 
the blue pigment contained in their cavities, with the doubtful 
exception of the part of the cecum immediately overlapping 
the “ brown body.” ‘This shows that the pigment taken up 
by the first generation of alimentary canals is really excreted, 
and that there is no (or at least very little) secondary absorp- 
tion of the pigment by the new polypides. 
I may remark incidentally that my observations, and Mr. 
Newstead’s continuation of them, give some information with 
regard to the amount of time necessary for the development of 
a “brown body” and the complete formation of a new poly- 
pide in this species of Flustra. 
One of the effects of the indigo-carmine on the colony was 
to induce the degeneration of all the polypides. This process 
was observed to be commencing rather more than four days 
after the immersion of the colony in the solution of the pig- 
ment. The further history of the experiment is explained by 
the following table. 
Colony treated with a Solution of Indigo-carmine. 
5th day (114 hours) . Polypides commencing to degenerate. 
7th ,, (165 ,, ) . Aggregation of granules of stomach and cecum 
into two masses. 
10th ,, (238 ,, ) . Appearance of young polypide buds. 
12th ,, (286 ,, ) . ‘Tentacles developed, the lophophore having be- 
come circular in the oldest individuals. 
13th ,, (805 ,, ) . Stage shown in fig. 3. 
15th ,, (853 ,, ) . Fusion of two masses of granules of stomach, &c. 
16th ,, (376 ,, ) . Tip of the cecum becoming connected with 
* brown body ” (fig. 4). 
Nth, MaeS 5s Dl Big. B. 
Qist ,, (496 ,, ) . ‘‘ Brown body” preparing to break up (fig. 6). 
26th ,, (622 , ) * Brown body” broken up into numerous frag- 
ments, contained in the alimentary canal of 
the new polypide. 
40th ,, (959 ,, ) . “ Brown body ” almost completely absorbed. 
The process of absorption of the ‘‘ brown bodies” was not, 
however, completed in all the individuals at the seventy-third 
day (1744 hours), the last observation recorded, It is, how- 
