in Gracilaria confervoides ? Grev. 221 
of the single fertilised procarpium with the surrounding pla- 
cental (auxiliary) cells. Indeed, much of the description of the 
development of the fruit of the Corallinaceae by Schmitz, but 
not by Solms-Laubach, will apply equally well to Gracilaria. 
The place of origin of the spores of Gracilaria represents a 
combination of the condition seen in the Helminthocladieae — 
the simplest of the Florideae, in the Ceramiaceae, and in the 
Cryptonemiaceae — the highest of the Florideae. 
Gracilaria , in its female apparatus, seems to stand in the 
same relation to the rest of Florideae as Chara does to the 
rest of Chlorophyceae. In most of the higher Florideae the 
procarpium, after fertilisation, becomes enclosed in a cellular 
sheath derived from the adjacent cells of the thallus. An en- 
velope, similar in time and place of origin, and in function, is 
found in most of the Coleochaeteae amongst the Chloro- 
phyceae. In Gracilaria , as in Chara , this cellular sheath is 
formed before fertilisation, a mark of greater specialisation. 
In a subsequent paper I hope to give an account of the pro- 
carpium and fruit of Sphaerococcus , of the family Sphaero- 
coccaceae, in which Gracilaria is placed. 
I must not conclude without acknowledging my indebted- 
ness to Dr. D. H. Scott, for his suggestion of this work and 
for kindly criticism during its progress. I would also take 
this opportunity to thank Mr. Thiselton-Dyer for the use of 
the Jodrell Laboratory, Kew, in which the greater part of this 
investigation was carried out. 
R 2 
