434 BOTANICAL GAZETTE [DECEMBER 
SAUVAGEAU succeeded in getting good cultures in which the 
zoospores germinated quickly to form a branched filamentous thallus 
of considerable extent, reaching a millimeter in diameter and forming 
hairs. When mature, cylindrical gametangia are formed with 
two to twelve loculi. Each cell forms a single gamete. The 
septae disappear before dehiscence, and the isogamous gametes 
escape by a terminal pore. Conjugation was not observed, but 
was undoubtedly present, for a part of the rounded up, quiescent 
cells produced from the gametes had two nuclei and two chromato- 
phores. Germination soon took place, and produced a short fila- 
ment which in a few weeks gave rise to an erect thallus with the 
essential structure of Dictyosiphon. 
It is a matter of peculiar satisfaction that the work of KLIN (10) 
definitely shows Chorda to have the same sort of life history as 
Laminaria. The vegetative similarities which this genus shows to 
the kelps are not sufficient alone to place it in the same family, but 
the demonstration of a precisely similar life cycle removes all 
question of the relationship. The gametophytes are considerably 
larger than those of Laminaria. Kyttn was able to confirm the 
cultural studies by some incomplete cytological details. In the 
vegetative cells of the sporophyte tissue there are present forty 
chromosomes. Reduction divisions take place in spore formation, 
and are followed by two vegetative haploid divisions. Good 
fixation was prevented by the paraphyses, and countable meta- 
phases were not found, but synapsis, diakinesis, and other condi- 
tions typical of the first reduction division were recognized. The 
number of chromosomes was about twenty, although it could not 
be determined precisely. In addition to the study of, the preceding 
species, Kirn has given details of at least part of the life cycle of 
several other genera in other families, which will be discussed in 
connection with the changes in the classification of those families. 
Recently SAuvAGEAU has discovered what he believes to be the 
gametophyte of Phyllaria reniformis in the tissues of Lithophyllum 
lichenoides (32). Finally, there has appeared a preliminary note 
by WILL1ams (38) relating to a detailed study of cultures of Lami- 
naria and Chorda, with descriptions of the gametophytes of these 
genera essentially as previously outlined. In addition, he men- 
