NATURE OF EXCRETORY PROCESSES IN MARINE POLYZOA. 129 
resemble that of B. neritina in containing numerous granules, 
which are, however, quite colourless, instead of being deeply 
pigmented, as in that species. They are spherical in form, 
and are highly refractive. When treated with iodine they 
assume a colour precisely similar to that taken on by starch 
under the same conditions.!_ This observation was made just 
before my departure from Naples, and I was unable to inves- 
tigate the subject with more care. Dr. A. Hansen has, how- 
ever, been kind enough to undertake to examine the reactions 
of these granules, which differ from starch in being readily 
soluble in dilute alkalies or acids. Iam inclined to regard the 
granules, which were noticed in the tentacles as well as in the 
general body-cavity, as a reserve supply of nutritive (perhaps 
carbo-hydrate) material. This is supported by the facts that 
they are most numerous at the growing edges of the colony, 
and that relatively few are present in any zocwcium which 
contains a brown body and an old embryo; indicating that 
the nutritive substance of the granules has been employed for 
the nutrition of the embryo. This granular funicular tissue 
is best developed on the sides and on the front wall of the 
zocecium. 
Depositions of orange pigment may be seen attached to 
various parts of the ectocyst, and enclosed in structures which 
are very similar to the ‘‘ Excretblaschen ” described by EHisig* 
in the Capitellide. They may assume the form of a number 
of minute granules or vesicles scattered through the substance 
of a cell, or of coloured granules contained in the interior of 
a more faintly coloured vacuole (fig. 13). They appear to be 
1 According to H. J. Carter (‘‘On the Identity in Structure and Composi- 
tion of the so-called Seed-like Body of Spongilla with the Winter-egg of the 
Bryozoa, and the Presence of Starch-granules in each,” ‘Ann. Mag. Nat, 
Hist.,’ ser. 3, iii, 1859, p. 381), starch-grains are present in the statoblasts 
of a species of Lophopus; while K. B. Reichert (“ Verg. anatom. Unt. iib. 
Zoobotryon pellucidus,” ‘ Abhandl. k. Akad. d. Wiss. zu Berlin,’ 1869, 
p. 281) describes, in the endocyst of Zoobotryon, certain bodies which he 
calls “‘ Amyloidkugeln,” which take on a “ Granatfarbe,” or even a violet 
colour, under the action of iodine. 
2 ¢ Fauna u. Flora G. v. Neapel,’ xvi Monographie. 
VOL. XXXIII, PART I.—NEW SER. I 
