66 BOTANICAL GAZETTE [JANUARY 
involves all of the protoplasm of this mother-cell, and the mitosis is a relic 
of times when more than one sperm was formed. The present binucleate 
sperm is a simple type of multinucleate gamete (coenogamete). 
Both male nuclei are discharged into the trichogyne of Nemalion, which 
at the time of fertilization contains no organized nucleus. One male 
nucleus passes into the carpogonium, in the upper portion of which it meets 
the female nucleus and here fusion takes place. Several sperms may 
unite with and discharge their contents into the trichogyne, but supernu- 
merary male nuclei soon break down. The fertilization of Batracho- 
spermum undoubtedly takes place in essentially the same manner as 
described by ScHMIDLE and OsTERHOUT, but both of these observers 
failed to understand the complications of the trichogyne. On the other 
hand, I was misled by these complications and failed to discover the essen- 
tial act of fertilization as a nuclear fusion in the carpogonium. 
The development of the cluster of fertile filaments (gonimoblasts) 
follows the older accounts, but WOLFE contributes a new point of impor- 
tance in showing that the carpospores are developed successively at the 
ends of the filaments. When one spore has been discharged the cell 
behind grows into the old cavity and develops there a new carpospore. 
This method of spore formation by successive proliferations is well known 
in certain groups of fungi, but among the algae has so far only been described 
for the Rhodophyceae. 
The cytological evidence that the cystocarp is a.sporophyte generation 
rests with a count of the chromosomes in mitotic figures at different peri 
of the life history. The number is about eight for the gametophyte, as 
shown in vegetative mitoses and during spermatogenesis. Mitotic figures 
were easily found at certain stages in the development of the fertile fila- 
_ ments (sporophytic), and these always presented an approximate double 
number of chromosomes, about sixteen. The numerical reduction of the 
; 
chromosomes seems to take place just previous to spore-formation, for — 
nuclear figures in the terminal cell of the older fertile filaments had quite — 
_ the same appearance as those of the gametophyte and showed eight chro- — 
Mmosomes. The manner of the reduction was not determined. 
WOLFE gives some interesting details of cell and nuclear structure. 
The chromatophore of Nemalion has the form of a hollow ellipsoid, the 
center being a vacuole and not a pyrenoid. The chromatin of the resting — 
nucleus is present in the form of a globular body (nucleolus). During — 
prophase the chromatin passes along fibrillae to the nuclear wall. The | 
spindle is intranuclear and centrosomes are present at its poles during ; 
metaphase.—B. M. Davis, The University of Chicago. 
