HISTOLOGY OF CERTAIN SPECIES ОҒ CORALLINACE Ж. 207 
are convex outwards, having very thick walls; but their walls are not usually perfect in 
outline. They have a double contour-line; and this ceases over а greater or less part of 
the position where cell-wall might be expected to be found. This absence is due prin- 
cipally to collapse of the cells after decalcification, and, to a certain extent, to the presence 
ofa lateral pore. (Plate XXVII. fig. 5.) 
The absorption of the adjoining cell-walls of cells and the conjugation noticed by 
Rosanoff have not been observed in the sense in which the terms are employed by that 
author. In the mass of the frond a large cell may be seen to have incomplete dissepi- 
ments at its distal end; but these are the beginnings of the sprouting of two perfect cells 
from it in order to multiply the series. This occurs largely all over the joints, and even 
in the outer layer, the increase being lateral there and in the direction of the periphery. 
V. The filamentous Processes of the Melobesi:x of the Bermudas. 
Like the Corallines, the Jelobesie live and flourish luxuriantly in the Bermudas; 
and it is interesting to announce that, like their artieulated allies, they present ex- 
ternal appearances of which no conception has been had by the observers in temperate 
climates*, 
The Nullipores chosen as the types upon which to explain the appearance of luxuriant 
external filamentation, and which form the subject for our plates, are two in number :— 
First, a very ramose species, with rather expanded ends to short and widely diverging 
branchlets. (Plate XXVII. figs. 10, 11.) 
The branchlets are solid, very concentric in their layers, and are minutely punctate. 
The fine hair-like growth from their external surface is wonderfully developed ; and the 
extremely delicate and greatly crowded filaments are as long as the branch is broad. 
They radiate in all directions. 
The second form arises from a stem ; and its branches, irregular in shape, inosculate, 
and ascend close together, so as to form a conical mass. (Plate XXVII. figs. 12, 13.) 
The crowded filamentous growth is placed around the branches, and extends outwardly 
from the frond to about one half of the diameter of the branch. 
It is evident that these filamentous growths are the analogues of those of the Coral- 
lines, and that all have the same important function in the nutrition of the plants. 
* Nullipores are closely allied to the Corallines both in structure and in their office in nature. Any one жын 
studied the blocks and masses of coral reef which the Sapper and Miner has blown up when they impede navigation, 
—or on which the naturalist has crawled, or round which he has been wading or swimming by the hour together— 
vilae dily admit the good service done, not only by Nullipora, but by many and many с йш ced 25525 
Vegetable Coral as а cement, cooperatively with the bond, at times, supplied by Gorgonide „ ш $ E im on : 
80-called Coral Reefs, іп а way quite distinct from the comparatively homogeneous proceedings in the structure 
Tubicola геев. —R. J. N. 
269 
