Developmental Forms of Marine Alga :. 237 
first the old plant, much torn and discoloured. From this proceed 
in all directions stalked wedge-shaped fronds, of distinctly more 
recent origin than the first. Upon their sides and surfaces new 
processes emerge in various stages of developement; these again 
may bear yet further proliferations. FI. Ill, Fig. 2a,b, c. 
Another species— Nit. Hillice —shows similar outgrowths. A 
specimen was gathered in quite a different locality, where there was 
moderate shelter; it is very large and old much torn and eaten. 
New portions are showing from the margins and occasionally from 
the surface, 
The following examples of recrudescence may also be cited. 
Final flabellations of an old plant of Callophyllis Habellata con¬ 
sisting of new tissue expand from narrow bases into quite 
appreciable flabellate fronds. 
A large and very old Callymenia Laterice Holmes, PI. I, Fig. 
2a, is thickly beset on surface and margins with reniform prolifera¬ 
tions. They are in all stages of growth, and have much the 
appearance of being new plants produced upon the old one, Fig. 2b. 
The same thing is happening on a plant of C. renifortnis in 
lesser degree. It is distinctly old, much torn or eaten, but new 
growths are issuing from its margin and surface. PI. II. Fig 
3, a, b. 
These structures are evidently growth forms arising as 
subsequent developments upon mature plants, and are quite distinct 
from the ordinary proliferations characteristic of a variety or species 
in which both frond and leaflet are of the same age. They are the 
result of tissue recrudescence, but the agencies which have induced 
it are still unknown. 
Mr. Gepp has suggested that the superimposed fronds may 
represent 2nd and 3rd year growths, and are actual plants 
developed in “situ” without having been detached. 
In the case of biennial and perennial plants, they would there 
fore be either renewals of growth for each successive year, or 
represent a process of propagation by proliferation. 
The development of new plants upon the old ones, and possibly 
at their expense, would assure the preservation of Ironds until a 
certain maturity is achieved and they would thus stand a better 
chance of establishing an independent existance when they break 
away from the parent. The specimens under consideration were 
