1910] CURRENT LITERATURE 227 
names. The volume is of moderate size and well printed, but the introduction 
of keys, especially in case of some of the larger genera, would have added some- 
what to the usefulness of the work in the identification of species. Nevertheless, | 
as a catalogue of the known species of the islands, it is a commendable contribu- 
tion to taxonomic literature and will serve as an excellent basis for future studies 
on the flora of the region.—J. M. GREENMAN. 
_Natiirlichen Pflanzenfamilien.t—Parts 236 and 237 contain a supplement 
to the Conjugatae and Chlorophyceae by the distinguished algologist Professor 
. WILLE. Two new genera. are included, namely Pseudopringsheimia and 
i ei 
oseny., an epiphyte growing on marine algae of the north Atlantic; the latter 
is based on Ulvella americana Snow, also an epiphyte, and occurs on freshwater 
algae of North America. Parts 238-240, likewise of recent issue, consist of a 
general index to Teil I of this great work.—J. M. GREENMAN. 
NOTES FOR STUDENTS 
_ The life history of Griffithsia—Lrwis has published a paper on the life 
history of Grifithsia Bornetiana. ‘The paper begins with the presentation of the 
vegetative characters of the three different individuals of this species: antheridial, 
Procarpic, and tetrasporic. The author records comparative studies of the size 
of the cells in the three individuals, di th t f intercellul tions, 
describes the division of chromatophores, and calls attention to the phenomenon 
of an approximate simultaneous occurrence of the nuclear divisions in multinu- 
cleate cells. There are then described the development of antheridia, cystocarps, - 
and tetraspores; the methods of vegetative propagation; germination of spores; 
and tetraspore-like struct n sexual plants. The paper closes with a discussion 
of results, in which the author presents his views on alternation of generations in 
Grifftthsia. 
Some of the cytological results are as follows. The nuclei in Griffithsia are 
throughout their history very poor in linin. The chromatin of the resting nucleus, 
therefore, is not distributed on a linin reticulum, but is chiefly contained in a cen- 
trally placed, homogeneous nucleolus or “‘karyosome.” As regards the mode 
of formation of chromosomes, the chromatin passes out of the nucleolus until 
the whole chromatin content is distributed through the nuclear cavity in the form 
of granules. These granules are much more numerous than the chromosomes, 
and probably by the fusion of separate granules chromosomes are formed. The 
number of chromosomes in the nucleus of vegetative cells in the tetrasporic plant 
PURI anc sen eee 
_ 4 ENGLER UND PRANTL, Die natiirlichen Pflanzenfamilien, etc. 236 and 237 
Lieferung. Conjugatae und Chlorophyceae von N. WittE. Nachtrige zum I. Teil, 
2 Abt., Bogen 1-6, pp. 96; 238 bis 240 Lieferung. Register zu Teil I (vollstindig), 
PP. 242, Leipzig: Wilhelm Engelmann. 1909, M 3, M 4.50. 
‘Lewis, I. F., The life history of Griffithsia Bornetiana. Annals of Botany 
23:639-690. bls. 49-53. 1900. 
