ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 
417 
segment, becoming later strictly ventral through the continued outward 
growth of the segment, and at the same time pendent from the ven- 
tral surface through the formation of a peduncle. The body of the 
“ tuber ” consists of a cortex of 2-4 layers of nearly empty cells, enclo- 
sing a mass of smaller cells densely filled with oil-drops or colourless 
granules. They are probably reserves of food-material, and assist in the 
vegetative propagation of the plant. 
Sporogone of Anthoceros.* — Herr Y. Liihne discusses the homology 
of the sporogone of Antlioceros with the sorus of ferns. The following 
are the chief points of resemblance of the Anthocerotem aud the Hyme- 
nophyllaceae : — (1) The germination of the spores, and the development 
of the prothallium of the latter and protoneme of the former, closely 
resemble one another ; (2) The sporogone of Anthoceros and the sorus 
of Hymenophyllum each possesses a central sterile receptacle or columel ; 
(3) Both organs exhibit intercalary growth ; (4) The sporogenous por- 
tion of the sporogone of Anthoceros is surrounded by a wall which 
detaches itself in the form of two valves, and which may be compared 
to the 2-valved indusium of Hymenophyllum ; (5) the sporogenous cells 
of Anthoceros and the sporange of Hymenophyllum t both develop basi- 
petally. The most important differences between the two have been 
held to be these : — (1) The sporogenous layer of the sporogone of 
Anthoceros belongs to the wall of the capsule ; while the sporanges of the 
Hymenophyllacese have their origin in the superficial layers of the re- 
ceptacle ; (2) The sporogenous cells of Anthoceros are directly isolated ; 
while the sporanges of the Hymenophyllacese develop from the recep- 
tacle as multicellular structures, developing the spore-mother-cells 
within them. 
Liihne now confirms the close relationship of the two families by 
showing that the sporogenous layer of the capsule of Anthoceros belongs 
in reality to the columel. He also suggests that the analogues of the 
sporange of the Hymenophyllaceae is to be met with in the spore-mother- 
cells of Anthoceros surrounded by elaters. 
Characese. 
Development of the Oogone in the Characese.f — Herr G. Goetz 
states that in Nitella ( flexilis ) the oogone originates in place of a 
lateral leaflet ; a cell of the node swells out and divides into three 
superposed cells. The lowermost of these forms the stalk-cell, the 
middle one the node-cell, and the uppermost finally develops into the 
true ovum-cell. In Chara ( foetida ), the oogone developes from the upper 
cell of the antheridial basal node, and again likewise divides into a stalk- 
cell, a node-cell, and an apical cell ; from the latter are developed 
the ovum-cell and the single Wendungszelle. In Nitella , after the 
formation of the three Wendungszellen , the ovum-nucleus continues to ex- 
crete nuclear substance, which passes into the germinal spot. In Chara 
nothing of this kind takes place. In the formation of the Wendungs- 
zellen there is no reduction of chromosomes. The fusion of the sperm- 
* S.B. Deutsch. Naturw.-med. Yer. Lotos, 1898, No. 1. See Bot. Centralbl., 
lxxvii. (1899) p. 164. 
t Bot. Ztg., lvii. (1899) 2 te Abth., pp. 1-13 (1 pi. and 3 figs.). 
