1907] CURRENT LITERATURE 293 
The early stages in the development of megaspores and also in the germination 
of the megaspore are normal; buta typical egg apparatus is not differentiated. 
The evidence that embryos are formed without fertilization is conclusive, but the 
evidence that some of the embryos may not come from nuclear tissue is not so 
conclusive. TREUB claims that the embryos come from contents of the embryo 
sac, but not from the egg, and consequently he uses the term apogamy rather 
than parthenogenesis.—CHARLES J. CHAMBERLAIN. 
Anatomical classification of ferns —FERNAND PELOURDE”® has attempted to 
discover an anatomical basis of classification for the ferns. A great amount of 
detailed structure is described, and, like every other attempt to use one kind of 
character, the result is a readjustment of some of the old taxonomic lines. The 
genera represented in France are described upon this new basis, but its applica- 
tion to a wider range of forms remains to be demonstrated. As an addition of 
certain characters, to be used in connection with all other available characters, 
the research is a contribution; but as presenting a set of determining characters it 
can hardly be accepted at this late day.—J. M. C 
Nomenclature of desmids.—NorDsTEDT”? has proposed the following rules 
of nomenclature for the desmids: (1) The nomenclature begins with 
British Desmidieae, 1848; (2) The authors of names given earlier and piecnel 
by Ratrs must always be cited. It is also suggested that standard works for 
other groups of algae may be used in the same way, as for instance: Hirn, Mono- 
graphie und Iconographie der Oedogoniaceen, 1900; BORNET et FLAHAULT, Revi- 
ston des Nostocacées hétérocystées contenues dans les principaux herbiers de France, 
1886-88 ; nen Monographie des ads (Nostocacées homocystées), 
1893.—J. M 
Chestnut disease.—In two additional papers Murrii1’° emphasizes the 
unusual destructiveness of a disease of the American chestnut first made known 
by him. This disease is so virulent that it threatens to destroy all the chestnut 
trees in New York City and perhaps over large areas. The cause of the trouble 
is a species of Diaporthe newly described as D. parasitica, From observations 
and from experiments it is evident that the fungus attacks the trees only b 
way of wounds. Attempts to infect young uninjured twigs and unfolding leaves 
gave negative results. No satisfactory treatment has as yet been found.—H 
HASSELBRING 
28 PELOURDE, FERNAND, Recherches anatomique sur la classification des 
fougéres de France. Ann. Sci. Nat. Bot. IX. 4:261-372. figs. 80. 1906 
20 Norpstept, C. F. O., The starting point of the nomenclature of desmids. 
Botaniska Notiser 1906:97-118. 
3° Murrit, W. A., A new chestnut disease. Torreya 6:186-189. 1906. 
» Further Signin on a serious chestnut disease. Jour. N. Y. Bot. 
Garden 7:203-211. figs. 2 . 1906. 
