74 ZOOPHYTES. 
and every new branchlet, though at first nearly horizontal, soon be- 
comes erect. The Madrepora prostrata, plate 33, figure 1, is a good 
example of this process, as well as the other corals of the same plate, 
and all the vase Madrepores. Were it not that the new budding-polyps 
were developed on the outer side of the branches, the zoophyte would 
at once lose its horizontal position. The branchlets in these species, 
after becoming erect, are symmetrical in their mode of growth. ‘The 
formation of parent-polyps, on the outer side of the main branches, is 
favoured by the more perfect exposure to the fresh ocean waters than 
is enjoyed in any other part of the zoophyte. 
This mode of branching produces generally arborescent forms, and 
is mostly confined to species budding from a parent-polyp. Yet the 
Gorgonie, Seriatopore, and Porites, afford examples of the same 
result, from parent-clusters. The wart-like prominences over the 
surface of a Pocillopora, may be produced by an analogous process. 
As the budding-cluster of the apex enlarges by growth, and the older 
polyps join those of the lateral surface, small clusters of two or 
three in each, at nearly regular intervals, retain the budding power, 
until these prominences have a certain length, usually not exceeding 
two lines. 
Budding of a branch. 
75. Besides the budding of a single polyp, there are some species 
which form a group at a single budding process. ‘This fact is pointed 
out by Milne Edwards, in his description of an Alcyonium.* A knob 
or protuberance swells out from the surface, which, on dissection, is 
found to be penetrated by tubes branching and subdividing towards 
the surface, and all proceeding from a common trunk, or a collection 
of trunks, which branch from one or more, as the case may be, of the 
old polyps. The young polyps were distinguishable at the extremi- 
ties of the tubes before they made their appearance externally ; and 
finally a cluster of animals was developed, and a new branch added 
to the zoophyte. ‘This process appears to be confined to this division 
of the Actinoidea. 
I]. Surrrior or Trerminat Buppina. 
76. While in /ateral budding, increase, in the prolate growth of a 
zoophyte, takes place from the extension of the lower part of the 
polyps, in terminal budding if proceeds from the extension of the 
summits. This process of widening in the budding-polyps may be 
confined to the parts exterior to the disk and visceral cavity below, or 
* Ann, des Sci. Nat., 2d Ser., iv. (1835.) 
