ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 
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connected with colonial formation may he prolate or acrogenous growths, 
or both. 
The colonial formation of stony corals is brought about by a number 
of processes of budding, each of which causes a certain characteristic 
growth ; the different forms may be grouped under certain heads. The 
simple young form may produce new persons in two ways — either by 
internal or by external budding. In the former process the calycinal 
cavities of the body and of the maternal calyx are directly connected, 
while they are not so in the latter ; the two modes of budding pass into 
one another. 
The following arrangement of the various processes is proposed 
A. Internal Budding. The budding is effected within the wall of 
the simple young polyp, and the calycinal cavities of the buds 
are directly connected with those of the maternal calyx. 
1. Partial Budding. The wall of the young is almost cylindrical. 
The buds are formed by a constriction of a part of the maternal 
calyx. (Partial -{- Septal Budding of v. Koch.) 
2. Coenenchym-Budding. The wall of the young is broadened 
out. The septa form a coenenchym in which new calycinal 
centres, which are not constricted, are formed. 
(Partly v. Koch’s Ccenencliym-Budding.) 
B. External Budding. The budding is effected outside the wall of 
the simple young polyp, and the calycinal cavities of the buds 
are not directly connected with those of the maternal calyx. 
3. Wall-Budding. The buds are placed directly on the wall of 
the maternal calyx. 
4. Costal-Budding. The buds are set on the costae, which are 
developed outside the wall. 
(Typical Coenenchym-Budding of v. Koch.) 
5. Stolon- Budding. The buds lie at some distance from the 
maternal calyx, and are at first connected with the latter by 
stolons. (Stolon-Budding of v. Koch.) 
If the soft parts and not the skeleton are considered, the same 
classification is arrived at. 
Well-marked partial budding is only possible when there is acro- 
genous growth, by which dichotomously branched trunks are formed 
(. Mussa ). Coenenchym-budding is connected with prolate growth, and 
gives rise to flat lamellae ( Phyllastrsea ). Wall-budding, in its typical 
form, gives rise to upright trunks, the branches of which are formed by 
a calyx ( Cyathohelia ). Costal budding gives flattened astraeoid colonies, 
and is always associated with acrogenous growth. Stolon-budding causes 
basal enlargements, from which the several calyces rise up. 
In most cases, however, the several processes of budding are not 
developed typically. It very often happens that such as require prolate 
growth are also connected with acrogenous growth so that curved broad 
colonies are formed, the surface of which may be branched. The 
several processes of budding are extremely characteristic of forms and 
even whole groups, for it is very seldom that, as in Leptastrsea , 
different modes of budding obtain in one species. 
The author regards Prof. Duncan’s recent classification as quite 
1890. 2 x 
