94 
BIBLIOGRAPHY. 
others contain from 10-32 (usually 16) zoospores, about two-thirds 
the size of those eight only of which are contained in a single 
sporangium. Mile. Karsakoff states that in Myriotrichia conjuga- 
tion takes place while both gametes are still actively motile, or at 
the instant they come to rest, but that perhaps the latter case is 
the rule. The process of conjugation is thus described by the 
authoress : — For two or three hours the liberated gametes, large 
and small, swim about in all directions. Little by little they begin 
to lose the power of motion, and approach one another in pairs, the 
large zoospores pairing with the little. They then roll one over 
the other, their hyaline portions come in contact, and little by 
little they combine, the larger zoospore appearing to absorb the 
contents of the less. After an hour or an hour and a half one sees 
that the two have united, to form a single coloured spore, with two 
red spots, which is larger than either of the zoospores which went 
to form it, taken singly. If the zoospores do not conjugate it 
appears doubtful, although they are capable of germinating, 
whether the plantules arising from them ever come to maturity. 
The unilocular sporangia of both species are spherical or ovoid, 
and contain an innumerable number of zoospores, about half the 
size of the smaller zoospores from the plurilocular sporangia. 
Under ordinary circumstances both M. filiformis and M. claves - 
formis are attached by horizontal creeping filaments spreading over 
the substratum, and strengthened by numerous rhizoids descending 
the lower articulations of the upright filaments. Together the 
creeping filaments and rhizoids form a dense cone or disc. When, 
however, these two plants grow on algae, which have a soft, velvety 
cortication, the case is different, and the horizontal filaments 
creep for a considerable distance, the rhizoids forcing their way 
into the tissues of the host plant. In cases of this kind it some- 
times happens that the unilocular sporangia are borne on the hori- 
zontal filaments. Mile. Karsakoff points out that this being the 
case it is needless to retain the genus Dichosporangium, of Hauck, 
which was separated from Myriotrichia because the sporangia were 
borne on the creeping as well as on the upright filaments. Mile. 
Karsakoff’ s paper is accompanied by an excellent plate. 
Les Algues de P. K. A. Schousboe. By E. Bornet. (“ Mem. Soc. 
Nat. Sc. de Cherbourg,” Yol. xxviii., 1892.) 
In a volume full of interest from beginning to end Dr. Bornet 
has given an account of the Algse collected by P. Schousboe, 
between the years 1815 and 1829, in Morocco and along the coast 
of the Mediterranean. Many new species are described in this 
volume, and notes of the greatest value and interest to algologists 
are appended to a large majority of the species mentioned. The 
geographical distribution of the species is also given, and the 
volume is illustrated by three very beautiful plates. Among the 
