148 BOTANICAL GAZETTE [FEBRUARY 
work contributes additional evidence showing that the line between autotrophic 
and heterotrophic nutrition is not so sharply drawn as is generally supposed. 
The power of the lower algae to use carbon compounds and especially the lower 
acids explains the abundant growth of those forms where decaying organic matter 
is present, as in contaminated waters.—H. HASsELBRING. 
Rhizomorphic root-rot of vine.—MaAcnus?S describes a rhizomorphic root-rot 
of the vine which causes a on of numerous ee | in the vineyards of certain 
regions of Europe. Th which may attain a diameter 
of 2™™, The strands lack a well- bs cortex, thereby differing from the 
characteristic strands of Armillaria mellea. The fungus is found to be abundant 
on the posts used as supports for the vines. From the posts the strands spread 
to the young roots of the vine, entwining and killing them. Although this dis- 
ease with the accompanying rhizomorphs had been known for several years, 
it was not until the present year that the connection of the rhizomorphs with one 
of the Hymenomycetes was established by finding numerous sporophores of 
Collybia platyphylla growing from the strands. As this fungus is very common 
in America, it is not unlikely that it may be connected with one of the numerous 
rhizomorphic root-rot diseases infecting our fruit trees.—H. HASSELBRING. 
Segregates of Rhus glabra.—GrEENE”® has studied the forms referred to 
Rhus glabra throughout its reputed range. He remarks that “there is no one 
species of tree or shrub of any continent that really holds the geographic range 
which the books and lists ascribe to Rhus glabra;” and points out the exceedingly 
diverse areas it is said to occupy in its continental distribution. Accordingly 
he has begun its segregation on the basis of such herbarium material as is avail- 
able, recognizing the fact that this is probably a very scanty showing of the real 
situation, for “‘no special call has been made for collecting these shrubs from 
different regions.”” The form chosen to stand for the original R. glabra L. is 
one ranging from eastern Virginia and southern Maryland through southern 
Pennsylvania to Connecticut. Outside of that region botanists will have to refer 
their reputed forms of R. glabra to other species. This initial work of segrega- 
tion has resulted in 29 species, 24 of which are new. —jJ.M.C. 
Transpiration.—ARESCHOUG maintains the correctness of his view that the 
Palisade tissue, when well developed and compact, reduces transpiration,’? 
explaining away certain apparently contradictory experiments of HESSELMAN 
and others. ; 
It seems to be about time to dismiss the idea of transpiration as a function, 
25 Macnus, P., pense eine Erkrankung des Weinstockes. Ber. Deutsch. Bot. 
gaia 24: 402-406. 190 
REENE, ABER re A study of Rhus glabra. Proc. Wash. Acad. Sci. 8: 
a 1906. 
27 ARESCHOUG, F. W.C., Ueber die Bedeutung des Pals dcepereichms fir die 
Transpiration der Blatter. Flora 96: 329-336. 1906. 
