ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 
827 
Fructification of Sphenophyllum.* — From an examination of the 
fertile spikes of Sphenophyllum cuneifolium from the Valenciennes basin, 
M. R. Zeiller identifies with it the Volkmannia Dawsoni of Williamson. 
He finds that the sporanges correspond in almost every point except 
their smaller size, with the sporocarps of Marsilea ; and he suggests that 
Sphenophyllum must be constituted into a distinct class of Vascular 
Cryptogams, most nearly allied to the Rhizocarpeae, though resembling 
the Lycopodinem in the structure of their axis. Binney’s genus 
Bowmanites must be sunk in Sphenophyllum. 
Algae. 
Trichomic Structures in Algse.f — According to Prof. M. Moebius, 
trichomic structures (in which term attaching rhizoids are not included) 
occur in all the main divisions of Algae, and vary greatly in their 
structure and development. They are found in all the sections of 
Florideas. In Batrachospermum vagum each hair consists of a long 
cylindrical cell, proceeding from a lateral or terminal outgrowth of the 
supporting cell. The outermost layer of the wall is finally burst, and 
forms a kind of sheath at the base of the hair. If the point is broken 
off, a new hair developes within this tube from the supporting cell. 
In the Phaeophyceae hairs are also very widely distributed. In Lami- 
naria digitata peculiar paraphyses occur in the middle of the sori. 
They are unicellular, and the cell-cavity is closed by a mucilaginous 
plug. In the Chlorophyceae structures of this kind occur especially in 
CEdogonium , Coleochsete , and Bulbochsete. The bristles of Coleochaete are 
outgrowths of the supporting cell, but are not cut off from it by a 
septum. The outer layer of the membrane in this case also bursts, 
and surrounds the base of the hair in the form of a sheath. 
Fructification and Thallus of Floridese.J — Prof. F. Schmitz makes 
some small corrections in his published descriptions of the sexual 
organs in Floridem. In Callithamnion the two auxiliary cells are impreg- 
nated by conjugation with the nearest small daughter-cells of the 
fertilized ovum-cell. A slight correction is made in the description 
of the formation of the procarp in the Rhodomelaceae. It is not the 
case that in Chondrus the cells of the meta-ooblast filaments conjugate 
with the cells of the adjacent sterile tissue, and that from this conju- 
gation the group of spores is developed ; but this is a correct description 
of the process in Mychodea . 
Prof. Schmitz further confirms his previous statement that the 
thallus of Floridem is in general composed of branched filaments which 
grow by continuous acropetal septation of the apical cell. This is true 
in a very large number of cases, though exceptionally a septum may 
arise here and there in a cell which is not apical. In some instances 
also such intercalary growth is normal, as in many Corallinaceas, and in 
all genera and species of Nitophyllese that have been examined. 
Systematic Position of Thorea.§ — Prof. F. Schmitz adduces argu- 
ments against Moebius’s view that Thorea belongs to the Floridem rather 
* Comptes Rendus, cxv. (1892) pp. 141-4. 
t Biol. Central!)]., xii. (1892) pp. 71-87, 97-108 (8 figs.). 
X La Nuova Notarisia, iii. (1892) pp. 110-9. 
§ Ber. Deutsch. Bot. Gesell., x. (1892) pp. 115-42. Cf. this Journal, ante , 
p. 239. 
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