298 BOTANICAL GAZETTE | ocTOBER 
admirably drawn, and bear the signature of Bertha S. Kimball. A key is 
arranged to aid in identification. J. W. Toumey (Ariz. no. 22, pp. 3-32) 
gives much general information about weeds of Arizona. In a list of 50 
species nearly three-fourths are not known, or rarely seen, east of the Missis- 
sippi river. Sixteen species are singled out for more extended description, 
against cockleburs and sunflowers along irrigating canals. A thick bulletin 
(Ore. no. 45) on prunes in Oregon, by four collaborators, contains a historical 
account of the varieties cultivated (pp. 21-33) and of the fungous diseases 
(pp. 63-75), written by U. P. Hedrick. An account of Cicuta vagans Greene 
is also given by U. P. Hedrick (Ore. no. 46, pp. 3-12, #2. ¢). The under- 
ground parts are very poisonous while dormant, a piece the size of a walnut 
being sufficient to killa cow. Two plates illustrate the plant, and two others 
show harmless species resembling it. F.H. Hillman (Nev. no. 33, pp- 3-13) 
gives notes upon a number of indigenous Nevada grasses, looking toward 
their utility as forage. In a bulletin by S. A. Beach (N. Y. no. 125) upon 
growing tomatoes under glass, two pages and one plate are given to a 
description of a peculiar black rot of the fruit written by F. C. Stewart. The 
cause was not ascertained. In the early stages no fungi or bacteria could be 
detected either by means of the microscope or agar cultures.—J. C. A. 
Dr. RoBERT BELL, of the Canadian Geological Survey, gave a very 
interesting address before the Royal Scottish Geographical Society at Edin- 
burgh last March on the geographical distribution of forest trees in Canada. 
This address has recently been published with a map.s_ The author is excep- 
tionally well fitted for this work by reason of forty years of observation 
throughout Canada. He states that there are 340 species of trees indigenous 
to the United States, 123 of which occur in Canada, 94 being found east of 
the Rocky mountains. Pinus Banksiana is mentioned as the only tree that 
may be considered as belonging to Canada, entering the United States only 
along the south shore of Lake Superior. It seems too bad to deprive the 
Canadians of the only tree to which they lay claim, but the species in ques- 
tion is very common about Lake Michigan, extending as far south as northern 
Indiana, The manuals also report Pinus Banksiana in Maine, Vermont, and 
New York. Some trees, especially the more hardy species, are said to taper 
off gradually in size as they approach their northern limits, while others, 
especially the more southern species, maintain their full size. The ormer 
habit would, of course, seem natural, owing to the gradually increasing rigor 
- northward. Dr. Bell attributes the differences to the fact that the first type 
have better means of distribution (e. g., seeds of conifers and poplars, fitted 
for wind dispersal), and have had time since the Pleistocene to occupy all 
territory congenial to their existence. The second type (including walnuts, 
$Scot. Geog. Mag. 13: 281-296. 
