NATURE OF EXCRETORY PROCESSES IN MARINE POLYZOA. 157 
and cecum of B. avicularia readily take up indigo-carmine, 
carminate of ammonia, or Bismarck-brown, and become less 
obviously red when the animals are fed with carmine in 
suspension. 
In B.neritina the same parts of the alimentary canal 
take up carminate of ammonia or carmine, but appear to be 
quite unaffected by indigo-carmine or Bismarck-brown. In 
F. papyrea the granules take up indigo-carmine or Bismarck- 
brown. The experiments made with carminate of ammonia 
and’with carmine were unsuccessful. 
Funicular Tissue.—This tissue is deeply pigmented in B. 
neritina, and readily takes up Bismarck-brown. In other 
species investigated the funicular tissue was for the most part 
colourless, and did not take up Bismarck-brown in the manner 
characteristic of B. neritina. Small quantities of this pig- 
ment and of carminate of ammonia might, however, appear 
in spherules apparently contained in cells of a specialised type, 
which may be regarded as belonging to the funicular tissue ; 
these spherules are often pigmented in their normal condition.! 
Young, slightly Differentiated Tissues of the Growing-points.— 
These tissues readily took up considerable quantities of car- 
minate of ammonia and of Bismarck-brown. 
It now remains to consider how far the experiments already 
described throw any light on the normal excretory processes 
of the marine Polyzoa. 
It can hardly be doubted that the pigments experimented 
with were actually excreted. This was clearly seen in the 
action of Bismarck-brown on the funicular tissue of B. neri- 
tina. The pigment was taken up so freely that it at first 
appeared extremely improbable that the animals could recover ; 
but at a later period it was deposited in an apparently insoluble 
form in various parts of the funicular tissue, leaving the 
remaining parts of that tissue quite free from it. In order to 
bring about this result the granules normally present in the 
funicular tissue had to be deposited with the Bismarck-brown 
1 For a more complete account of the absorption, by various tissues, of the 
pigments experimented with, see the earlier part. of the paper. 
