NOTES AND ABSTRACTS. 523 
deterioration, the meristematic as well as the specialized tissues should undergo 
such change. 
It would seem that the logical method of attacking the problem is by a careful 
comparison of the same organ in young and old plants of the same genus for 
evidences of senile deterioration in structure or function. The wild grape {Vitis 
vulpina L.) was chosen because it puts forth new growth each year, in order to 
minimize, as far as possible, the chance of the presence of unfavourable conditions 
other than age. Investigations upon young and old leaves on veining, photo- 
synthetic activity, respiration, and imbibition were made, and the following 
results were obtained : — 
The vein islets in the leaves of Vitis vulpina become smaller as the vine 
becomes older. This decrease in size is due to the encroachment of vascular 
tissue ; and this decrease means reduction in size of " photosynthesizing " cells, 
and therefore a decrease in rate of photosynthesis. 
There is also a decrease in the rate of respiration in picked leaves. 
Leaves of young vines have a greater capacity for imbibing water than have 
leaves of old vines, which may be due to less vascular tissue in the former. 
There is an increase with age in the number of stomata per sq. mm. There 
is probably a decrease in the size of the palisade cells, and in the size of the nuclei 
in the parenchymatous cells, as the leaves increase in age. 
A short bibliography is appended. — A . B. 
Walnuts, Crossing of. By Max Garmer {Rev. Hort. July 16, 1916). — Illus- 
tration showing three varieties. Note on various French hybrids. — C. T. D. 
Water Melon Stem-end Rot. By F. C. Meier (Jour. Agr. Res. vol. vi. No. 4, 
April 1 91 6, pp. 1 49-1 52 ; 2 plates). — For some years in certain parts of the South- 
ern States of America, a decay and rot, which attacks water-melons (Citrullus 
vulgaris) in transit, and sometimes destroys them completely, has been noticed . 
The author has isolated a fungus which bears pycnidia and possesses many 
of the characteristics of the genus Diplodia. It is well known that Diplodia spp. 
attack numerous tropical crops, including sweet potato (Ipomoea Batatas), 
cotton (Gossypium), rubber (Hevea spp.), cocoa (Theobroma Cacao), tea (Thea 
spp.), as well as the various species of Citrus. — A. B. 
Weeds. By J. H. Maiden {Agr. Gaz. N.S.W. vol. xxvii. pp. 29-39 and 235- 
246). — Blue Couch Grass {Cynodon incompletus) is poisonous at some seasons ; 
Corn-cockle {Agrostemma Githago), some of the Sundews (Drosera), Oleander, 
Stipa robusta, Nicotiana suaveolens are dangerous to stock. Datura Stramonium, 
Nicandra physaloides, Hemlock (Conium maculatum) are poisonous, and Euphorbia 
Drummondii, Stachys arvensis, Anagallis arvensis, Crotalaria, and Echium vulgar e 
are suspect. 
Weeds are spread in manure even if it is well rotted. Always use screened 
seed of good quality. Prevent weeds from seeding. Burn, do not bury weeds. 
Eradicate if possible. Weeds are harboured on waste land, such as neglected 
cemeteries and the strips of land adjacent to the railway tracks in Australia. 
5. E. W. 
White Pine Blister Rust. By Perley Spaulding {U.S.A. Dep. Agr., Bur. PI. 
Ind., Farm. Bull. 742, June 1916, pp. 1-15 ; 5 figs., 1 plate). — This disease is 
caused by a fungus, Cronartium ribicola Fischer (Peridermium Strobi Klebahn) ; 
it attacks the white pine, and has an intermediate host in various species of 
Ribes. It causes much damage to pines in the North-Eastern States of America, 
and is said to have been introduced from Europe on imported seedlings of pines . 
Pinus Strobus, P. monticola, P. Lambertiana, P. excelsa, and other species of the 
5-needle-leaved pines, may be attacked by this disease. 
A brief account of the life-history of the fungus is given, and an account of 
the measures of control adopted in Europe and America detailed. A most 
drastic measure for each federal State is advocated, in order that the pest may 
be completely controlled, and finally eradicated. — A. B. 
Wistarias of China and Japan. By E. H. Wilson (Gard. Chron. Aug. 5, 1916, 
p. 61). — Enumerates four species and many varieties. W. multijuga of gardens 
is shown to be W. floribunda, and W. brachybotrys is W. venusta, but sinensis 
stands for the well-known and first introduced plant. W A japonica has pale 
yellow flowers. — E. A. B. 
Wood-using Industries of Ohio. By Carroll W. Dunning {U.S.A. Exp. Stn., 
Ohio, 1912). — With her many|'rail andtwater transportation facilities, and with 
her vast resources of soil, forests, coal, oil, gas, iron, stone, and clay, Ohio 
