752 
SUMMARY OF CURRENT RESEARCHES RELATING TO 
Algae. 
Anamorphic State of the Lower Algae.* — Prof. A. Borzi has in- 
vestigated the life-history of the green algae comprised in the family 
Pleurococcaceae f of Dangeard and Klebs ( Pleurococcus , Raphidium , 
Scenedesmus , Dactylococcus, Siichococcus, &c.), and has come to the con- 
clusion that they constitute a stage of development of algae belonging to 
other families which he terms “ anamorphic.” 
If the zoospores of Ulothrix flaccida are observed at the moment 
of escape, it is seen that some are endowed with an irregular vortical 
motion different from the others. These are pairs of zoospores which 
have coalesced at the extremity opposite to the beak, forming a fusiform 
body, straight, or more or less curved, or with the form of a V, with a 
cilium at each extremity. These bodies move rapidly through the 
water, and ultimately multiply by longitudinal oblique bipartition into 
fusiform or semilunar cells, having all the characters of Raphidium ; 
when still united into colonies they constitute the genus Actinastrum 
Lagh. Similar raphidio-forms were observed of Protoderma , Stigeo- 
clonium, Eermonema , Chloroclonium, and Prasiola. 
A stichococcoia form can be induced in TJlothrix flaccida by growing 
the filaments under conditions of imperfect aeration ; the cells lose 
their close connection with one another and become partially separated, 
with exceedingly thin walls. Whenever filaments in this condition grow 
on a substratum of a fungoid nature, a symbiosis or commensalism 
between the fungus and the alga seems to occur. This bacillar form of 
Ulothrix constitutes the genus Arthrogonium A. Br. 
Bulbotrichia.t — M. P. Hariot agrees with Bornet, de Toni, and 
de Wildeman, in abolishing this reputed genus of Algae. Two distinct 
organisms have been included under this name ; one is a lichen in the 
structure of which partake gonids belonging to different groups of algae, 
and not merely to Protococcus ; the other is an autonomous plant be- 
longing to the genus Nylandera (TrentepohliaceaB). 
New Algae and Schizophyceae.§ — Prof. A. Hansgirg describes, under 
the name Gloeotsenium, a new genus of fresh-water Algae, which he pro- 
poses as a member of a new family, Pseudodesmidiace.®, intermediate 
between the DesmidiaceaB and the Palmellaceae. It is distinguished from 
Palmellaceae either by the peculiar development of the gelatinous enve- 
lope, or by the formation of zygotes ; from the Desmidiaceae by the struc- 
ture of the cell-membrane, which does not consist of two distinct similar 
pieces, and by the cell contents being arranged cylindrically instead of 
bilaterally and symmetrically. The family will include the genera 
Spirotsenia, Cylindrocystis, and Mesotsenium , to which Hansgirg adds 
Glceotsenium , although no sexual reproduction has yet been detected in it. 
The following new species, from Bohemia, Carniola, Istria, and 
Dalmatia, are also described : — Chantransia incrustans , forming a dark 
olive-green incrustation on stones ; Endoclonium (?) marinum , on mussel- 
shells and stone ; E. (?) rivulare , on stones and wood ; Hormospora suh- 
tilis ; Oocystis pusilla , in springs on limestone and marble ; Glceotsenium 
* Nuov. Giom. Bot. Ital., xxii. (1890) pp. 403-9. 
t Cf. this Journal, 1889, p. 96. X Notarisia, v. (1890) pp. 993-6. 
§ SB. K. Bohm. Gesell., 1890, pp. 1-20, 29-33 (2 pis.). 
