318 BOTANICAL GAZETTE [APRIL 
Oltmanns’ studies have led him to conclusions that may be stated 
very briefly. There is only one sexual act and that occurs in the carpo- 
gonium. The structure derived from the fertilized carpogonium is 
comparable to the sporophyte generation of higher plants. The plant 
that bears the sexual organs is the gametophyte. ‘Tetraspores are 
special forms of reproductive cells that have no fixed place in ontogeny. 
The fusion of the carpogonium or filaments derived from the carpogo- 
nium (sporophytic) with auxiliary cells (gametophytic) is for purposes 
of nutrition. The sporophyte is dependent upon the gametophyte in 
a manner analogous to the conditions illustrated by the bryophytes. 
Indeed, in certain instances, the sporophyte holds a relationship to 
the gametophyte closely similar to that of a parasite upon its host. 
The act of fusion between cells of the sporophyte and the auxiliary 
cells concerns the cytoplasm alone. In all such instances the spor0- 
phytic nuclei remain apart from the nuclei of the gametophyte. te 
never come together and unite, but rather appear to take up positions 
somewhat remote from one another. The gametophytic nuclei become 
less prominent as the cystocarp develops, and finally may be very 
inconspicuous, or even break down and disappear. The carpospores 
are developed through the activity of sporophytic nuclei, and sep 
are genetically derived from the fusion nucleus that resulted from the 
copulation of male and female elements in the carpogonium. 
These conclusions of Oltmanns are the results of aan 
upon four genera of the red alga, Dudresnaya, Gloeosiphonia, : 
thamnion, and Dasya. The descriptions are clear, and the pres 
figures will be greatly appreciated by those who know the sa? a 
of this field of study. The evidence would be convincing, were 
for the absence of certain critical stages of nuclear fusion and nuc 
division. Perhaps it is not fair to expect such exactness and = ” ea 
detail in this first presentation of Oltmanns’ theories, and t fe 
sumptions are certainly in favor of the correctness of his —— 
However, someone must complete the chain of evidence before 
consider the proof as absolute. 
The account of Callithamnion is perhaps the most 
tribution in the paper, since it concerns a well-known Lith 
type. Oltmanns finds that the fertilized carpogonium in Ca o 
corymbosum divides into two cells, which extend on cal the side 
the auxiliary cells. A small cell, cut off from each of ae a nucleus 
nearest the auxiliary cell, fuses with the latter. A sporoP®y 
interesting ” 
d much studi 
amnion 
