1916] CURRENT LITERATURE 423 
egg, soon develops a wall about itself, separating it oie the abandoned tube. 
Sometimes the embryospore nucleus divides, giving two cells; then the anterior 
cell behaves like an ordinary embryospore; or if a monosiphonous filament of 
several uninucleate cells is formed, the anterior cell again functions. Only in 
weak and poorly developed cultures did SaUVAGEAU observe erect branches 
from the embryospore; in these cases each erect branch behaves in the manner 
described. 
If the embryospore is to develop a male gametophyte, its diameter is 
increased little or none, elongation is very rapid, but the entire structure 
remains very minute. The antheridia develop as rounded colorless buds, each 
enclosing a single sperm, which after its escape is seen to be motile, colorless, 
and laterally biciliate. 
Fertilization was not observed, but SAUVAGEAU assumes that it occurs 
and that from the fertilized egg the plantlet or sporophyte develops imme- 
diately. His account from this stage on differs in few essentials from the 
accounts of other workers, the stipe and blade being differentiated at a very 
early stage. 
It is to be regretted that at the critical stages details are not more clearly 
given. However, it is evident from this account, as also from that of Drew, 
that there are certain phases in the life history of the Laminariaceae which are 
in need of critical investigation, especially from a cytological point of view. 
Drew concluded that as a result of conjugation of isogamous gametes a fila- 
ment (the sporophyte) developed which in turn gave rise to the plantlet (the 
gametophyte). Sauvacrau concludes that the gametophyte comes very early 
in the cycle; in fact, it is practically a walled zoospore, and the plantlet which 
is produced as the result of fertilization of the egg is the sporophyte. It would 
Seem that a careful investigation might clear up the haziness w still 
remains about these phases in the life history —MABet L. Roe. 
Tannins.—MoeE er? has noted peptization phenomena in tannin solu- 
tions, and believes that they form the basis of the process of tanning. A 
tannin extract contains two sorts of substances: (1) a tannin that is soluble 
in water, and (2) an accompanying substance, a gel, which is insoluble in water. 
With pyrogallol tannins this accompanying substance is called ellagic acid, 
and with pyrocatechin tannins it is called phlobaphene. The ellagic acid and 
et, while insoluble in water, are soluble in the tannin solution; that 
S, the tannin peptizes the ellagic acid gel and the phlobaphene gel, the tannin 
peng called the peptizator and the gel the peptized substance. In the process 
of tanning the hide adsorbs the peptizator and the gel coagulates out, sur- 
rounds the fibers of the hide, and leather is formed. He says a true solution 
cannot tan a hide, but only a peptized solution, and that all tanning solutions 
° Mor nb Die oo in Gerbstofflésungen. Kolloid. 
Zeitsch, a Sees 
