24 Brannon . — The Structure and Development of 
frond from small portions which have been cut from the 
parent plant. 
7. It is found by experiment that the carpospores and 
tetraspores are excellently adapted to the study of the various 
phenomena attending germination, for while they respond 
readily to change of intensity of light, temperature, and salinity 
of the surrounding water, yet they are sufficiently hardy to 
develop into young plants when artificially supplied with 
favourable conditions. 
8. The non-motile antherozoids are developed in enormous 
numbers by the abstriction of the terminal portion of the 
apical cells of the antheridia. 
9. The cystocarp begins to develop by the modification 
and apical growth of a joint-thallus-cell. 
10. The procarp, consisting of three cells, is developed from 
the supporting thallus-cell in the base of the young cystocarp. 
Its apical cell becomes the carpogonium. Subsequently, the 
fertilized contents of the carpogonium are transferred through 
the open pores connecting the procarpic cells to the sup- 
porting thallus-cell which becomes the central one of the five 
auxiliary cells. 
11. The trichogynes are often branched, and as many as 
five simple ones may grow from a cystocarp borne on a 
proliferation. 
12. Fusion of the antherozoid with the trichogyne results 
in great stimulation to the thallus-cell at the base of the 
procarp, and rapid disintegration of the trichogyne, which is 
a very evanescent organ. 
13. The sporiferous filaments are developed as chains of 
central cells, from each of which a whorl of spore-producing 
threads may originate. 
14. The carpospores arise acropetally from the branches 
of the sporiferous filaments, and not interstitially. 
15. The development of the cystocarps of Grinnellia agrees 
with that reported for Gracilaria in that the body-cavity 
develops schizogenetically, and that the sterile filaments 
connect the pericarp with the cortical tissue below the group 
