1905] * CURRENT LITERATURE 375 
be pteridospermic, as is expected, it will serve to emphasize the evidence of the 
fossil wood (Dadoxylon) as to the occurrence of gymnospermous-like plants in 
the middle Devonian (Genesee), a time nearly as remote as that furnishing the 
oldest known ferns of undoubted authenticity, and would seem to render the search 
for ancestral forms of these comparatively highly organized pteridospermic types 
futile—The same author gives'® a systematic account of the Devonian flora of 
the Perry basin, Maine, listing twenty-nine species, not including nine more or 
less doubtful species which Dawson reported from this locality. Several new 
generic and specific types are described, and numerous nomenclatorial points are 
cleared up. The paper is fully illustrated —Epwarp W. BERRY. 
CLAUSSEN” gives an account of the life history of the ascomycete Boudiera. 
The sexual organs consist of short filaments which are developed in clusters and 
become very much twisted together, presenting spirally wound structures some- 
what resembling the sexual organs of Gymnoascus. These filaments are differ- 
entiated into antheridia and ascogonia which fuse. After fertilization a cluster 
ascogonium, containing several nuclei, which bears a terminal sterile cell, perhaps 
0. The nuclei in the sterile cell break down, and it finally becomes the medium 
(conjugation tube or trichogyne) through which the protoplasm from the anther- 
idium enters the ascogonium. The antheridial filament is thinner and also con- 
tains several nuclei, which after the fusion with the sterile terminal cell pass into 
the ascogonium. The fertilized ascogonium then contains some ten or twelve 
nuclei and the antheridial filament and sterile terminal cell are empty. The 
nuclei in the fertilized ascogonium fuse in pairs. The empty antheridial filament 
and sterile cell collapse. The fertilized ascogonium increases in size, the fusion 
nuclei become conspicuous, and it finally divides into several cells by cross walls. 
The ascogenic hyphae are very short and the tips take at once the form of a hook 
and contain four nuclei. One nucleus lies in the tip, another in the stalk, and the 
remaining two in the bent portion of the hook. The four- nucleate condition is 
derived from a two- nucleate, but the preceding history is not known. e pair 
of nuclei in the bent portion of the hook become separated by walls from the tip 
and base of the filament and shortly coalesce; this cell becoming then a young 
ascus containing the single fusion nucleus. Thus each ascogenic hypha develops 
a single ascus. The terminal cell remains indefinitely, but there is no development 
from it. Several asci are formed from one ascogonium, but not simultaneously. 
Their number is believed to agree with the number of fusion nuclei in the ascogo- 
nium. The process of aor formation appears to follow HARPER’s account, but 
LL 
8 WuiTE, Davip, Smithsonian Miscellaneous Coll. 47: 377-39°- pls. 53-55: 1995- 
*9 CLaussEN, P., Zur Entwickelungsgeschichte der Ascomyceten Boudiera. Bot. 
Zeit. 631: 1-28. pls. I-3. 190 
