NATURE OF EXCRETORY PROCESSES IN MARINE POLYZOA. 133 
noticed in the normal zocecium, occur here and there in the 
diffusely coloured portions of the cell (figs. 23 and 24). In 
many cases large complexes of these cells occur in various 
parts of the zocecium (fig. 23). The absorption of the indigo- 
carmine is independent of the functional activity of the ali- 
mentary canal. The general funicular tissue remains un- 
coloured. 
In many of the zocecia occur structures which are figured by 
Haddon! in Pl. XXXVIII, fig. 12 (/.c¢.). These structures 
occur near the posterior wall of the zocecium, either on one or 
on both sides. They are not found in all the zocecia, and are 
not recognisably present in those which are near the growing 
edges of the colony. They do not appear to have any special 
connection with the exterior or with the rest of the funicular 
tissue. They consist externally of a membrana propria, out- 
side which are a few orange granules, the interior of the cord 
being finely fibrillated. 
Freese? mentions the finely granular character of these cords 
in Membranipora. Nitsche? had previously termed them 
‘‘funiculi laterales”’ or “ lateral cords,” and had stated that 
they passed from one rosette-plate to another. Their contents 
are sometimes granular according to Nitsche.* 
When still incompletely developed the lateral cords are not 
affected by indigo-carmine ; but in their older stages they in- 
variably take up a large quantity of this pigment, which 
appears to be contained in the membrana propria, outside 
which is a layer of cells containing the orange-yellow granules 
(Pl. LL fig. 7). 
Indigo-carmine is taken up by the granules of the functional 
alimentary canals only. The first part of the stomach and 
1 «Quart. Journ. Mier. Sci.,’ vol. xxiii, 1883. 
2 W. Freese, “ Anatom.-histol. Unt. von Membranipora pilosa,” &c., 
‘Arch. f. Naturg.,’ Jahrg. 54, Bd. i, 1888, p. 16. 
3 H. Nitsche, “ Ueb. d. Anat. u. Entw. von Flustra [Membranipora] 
membranacea,” ‘ Zeits. f. wiss. Zool.,’ Bd. xxi, 1870, pl. xxxv, fig. 1; pl. 
xxxvi, fig. 9. 
4 Loe. cit., p. 425, pl. xxxvii, figs. 19, 20. 
