Lewis . — The Life History of Griff thsia Bornetiana . 677 
event the cells bearing numerous branches become thick- walled and 
almost globose in shape. 
It is interesting to note that when numbers of sporelings are found in 
immediate vicinity in nature, all are often at precisely the same stage of 
development. For instance, about fifteen sporelings were observed on 
a single branch of Lomentaria ; all were at the stage of germination 
represented in Fig. 158. 
Hairs are usually wanting in the young plants, nor are rhizoids 
developed except from the basal cell. 
The phenomena of germination noted above agree in all essentials with 
the account of Griffithsia Bornetiana given by Miss Derick (26), and are in 
line with the phenomena reported in other species by Tobler (85). 
It is of considerable interest that the coenocytic condition characteristic 
of the cells of the mature plant is attained in the sporeling before any sign 
of cell-division or differentiation. The recapitulation theory 1 has been 
shown in many cases to be applicable to other plants, e. g. in the formation 
of the megaspores of the Hydropteridineae (Strasburger, 79), in the forms 
of juvenile leaves (Berry, 5), in the post-embryonal stages of the Laminaria- 
ceae (Setchell, 72, and Griggs, 34), in the formation of the eggs of the 
Fucaceae (for the facts, see Oltmanns, 59, ii, pp. 47-8). If this theory is at 
all applicable to Griffithsia , we should expect some evidence of it at the 
times in the life-history when the plant returns to the unicellular condition. 
If there is virtue in the conclusions drawn from comparative morphology, 
the ancestors, and even the comparatively recent ancestors of Griffithsia , 
possessed uninucleate cells. The coenocytic habit was acquired late in the 
history of the race, and we should expect it, therefore, to appear late in the 
history of the individual, so that the cells of the early stages would be 
uninucleate ; yet in the germinating spore of Griffithsia the first visible 
change is the attainment of what we must regard as the recently acquired 
coenocytic habit. In this respect, then, Griffithsia does not conform to the 
recapitulation theory. 
Discussion of Results. 
From the cytological evidence brought forward in this paper it seems 
probable that there exists in Griffithsia Bornetiana an alternation of 
generations similar to that which has been suggested for Polysiphonia 
violacea (Yamanouchi, 93). The fusion nucleus, which contains fourteen 
chromosomes, with the co-operation of the cytoplasm of some of the cells 
of the procarp, produces the cystocarp, in which are formed carpospores ; 
1 ‘A highly organized plant, which begins its development with the simplest stages and 
gradually advances to a state of higher differentiation, repeats in its ontogeny its phylogenetic 
development.’ Strasburger, Noll, Schenck, and Schimper : A Textbook of Botany, Second English 
edition, 1903, p. 49. 
Z Z a 
