iJOOLOGlCAL LlTERATUiUi. 
30Q^ 
Multiplication of the Colony by Budding outwards. 
Among tlie encrusting Polyzoa, Mr. Smitt selects Flustra 
membranacea (pi. 1. figs. 1-10). Along the margin of the entire 
colony will be found a bulging out^ consisting of Fettkroppai’j 
included in a membrane. (Following Henle^ the word Fettkroppar 
is employed for those structures which^ found in the body-fluid 
of the lower animals, would appear to correspond to the lymph- 
bodies in the higher animals. Williams calls them ^^floating- 
cells In all the cells the budding commences inwardly as an 
inflation at the base of the cell (fig. 3), the membrane around the 
bud grows out over its top (figs. 5 & 6) and grows on to the ten- 
tacle-sheath (figs. 7-10). At the base of the bud it is cut off from 
the endocyst and grows firmly about the base of the tentacles. 
In the meanwhile the great retractor muscles are developed, and 
in the loose cellular tissue the pharynx. Stomachal and rectal 
expansions originate as three distinct cavities, which afterwards 
communicate with one another. Two semicircular concentric 
lines of growth appear on the endocyst, and form the operculum ; 
the paricto- and parieto-vaginal muscles also become developed 
from the mass of Fettkroppar. Such is the general process of 
budding outwards, which is sometimes combined with fusion. 
The development after this fashion is described in Lepralia paU 
lasiana (pi. 1. figs. 11 & 12, pi. 2. fig. \)y Scr'upocdlaria scruposa 
(pi. 1. figs. 13 & 14), Crisia eburnea (pi. 1. figs. 15-18), Diasto- 
pora obelia (pi. 4. figs. 15 & 16), JEtea truncata (pi. 2. figs. 5-14, 
pi. 3. figs. 1-8), and Membranipora pilosa (pi. 2. figs. 2-4) : spe- 
cial difierences in each of these forms are pointed out in detail. 
The multiplication of the Polyzoa may therefore be said to take 
place by means of a collective bud (Samknop) \ and at the very 
commencement of each budding outwards this bud will be 
found to have the same individual composition. A transposition 
of this form of development shows that the mass of Fettkroppar’ 
takes part also in 
The formation of Ova by Budding inwards. 
Such a process takes place in the formation of ova in Lepralia 
peachii (pi. 3. figs. 9-11) . The ovum is first seen as it lies in the 
cell imbedded in a loose mass of Fettkroppar collected along 
the side of the body-cavity; the ovum has already acquired its 
membrane and its red colour. As it increases in size the Fett- 
kroppar-mass diminishes about it, till at last it lies free in the 
body-cavity ; from which it passes to the ovicells, in order there 
to complete its development ; it now undergoes segmentation, 
and ultimately the embryo becomes ciliated. The cilia are of two 
sorts : the smaller and more closely packed arc the more active ; 
the larger, which, while the embryo is still Muthin the ovum, can 
be recognized by their waving and slow movements, arc scattered 
