236 BOTANICAL GAZETTE  [SePreupee 
SCHOTTLANDER’S statement that centrosomes are present during the diaster and 
dispirem stages in young antheridia is also confirmed. Centrosomes were found 
throughout the spermatogenous divisions, during which they perform the ordi- 
nary functions of centrosomes. They do not persist throughout the life history 
of the cell, but appear at the beginning of each mitosis and disappear by the time 
the dispirem stage is reached. After the spermatogenous divisions have ceased, 
the centrosome reappears, functioning not as a centrosome but as a blepharoplast 
giving rise to the cilia. IkeENo interprets as genuine centrosomes the blepharo- 
plasts of various pteridophytes and of the cycads and Ginkgo. 
According to current accounts, the spermatogenous tissue, at the close of the 
spermatogenous divisions, consists of approximately cubical sperm mother-cells 
each of which gives rise to a single spermatozoid. The present investigation 
shows that there is still another nuclear division in a diagonal plane and not 
followed by the formation of a cell wall, so that each sperm mother-cell gives 
rise to two spermatozoids. This is true not only for Marchantia, but probably 
for other liverworts also. At this diagonal division, the centrosomes, after func 
tioning as centrosomes, do not disappear, but persist and function as blepharo- 
plasts. The blepharoplast elongates, and its body comes into close contact with 
the inner surface of the spermatid cell, so that it appears like a thickening of the 
Hautschicht. From this elongated centrosome, or blepharoplast, come the two 
cilia. 
Shortly after the diagonal division a peculiar spherical body, staining some 
what like the centrosome, appears in each spermatid mother-cell, but 1s readily 
distinguished from the centrosome by its larger size and its position. It is still 
distinguishable after the centrosome has given rise to the cilia. From the resem 
blance to the chromatoid body of some animals, the same name is suggested a 
this body. Occasionally each of the cells resulting from the diagonal ac 
divides. Such a division is accompanied by a division of the chromatid Po¥ 
and of the centrosome. Thus four spermatozoids would be formed from ¥! 
is usually denominated a sperm mother-cell. However, only (we spermat of 
mature, the supernumerary ones being used for nutrition. This homol 
the centrosome is fully discussed.—C. J. CHAMBERLAIN. ; 
PROBLEMS CONCERNING WATER ABSORPTION by epiphytic ea 
have been investigated by Mrz,4" who has gone carefully over the gre 
ersed a few years ago by Scuimprr. He agrees with SCHIMPER pe per 
lars, but is at variance with him regarding the behavior of the indivi ia oy 
during water absorption. ScurmpER claimed that the four central pi plant 
cells of the shield part of the scale are filled with air when the surface of hee 
is dry, and that the air is replaced by water when the surface is wet- vities of 
microchemical tests, as well as by direct observation, finds that the 
cass ete eee etn i 
_Qekonomit 
4* Mrz, Cart, Physiologische Bromliaceen-Studien. I. Die ee figs: - 
der xtrematmospherischen Tillandsien. Jahrb. Wiss. Bot. 40: 157 
€ 
1904. 
