NOTES AND ABSTRACTS, 
485 
Cherry Tree Manure {Qu. Agr. Jour. Nov. 1915, p. 258). — 2 to 4 lb. 
superphosphate, 1 to 2 lb. sulphate of potash, 1 to i| lb. nitrolim or sulphate 
of ammonia to a tree ; or 1 lb. superphosphate, 2 to 4 lb. bone-meal, 1 to 2 lb. 
sulphate of potash, and 1 to 2 lb. dried blood to a tree. — C. H. H. 
Chestnut Blight Fungus {Endothia parasitica), Ascospore Expulsion of. 
By F. D. Heald and R. A. Studhalter (Amer. Jour. Bot. vol. ii. No. 9, Nov. 1915, 
pp. 429-448 ; 6 figs.). — The effect of moisture upon the expulsion of the ascospores 
of Endothia parasitica (Murr.) And., has been frequently studied, but little 
work has been done on the seasonal duration of ascospore expulsion in this 
organism. It seemed desirable to have continuous records of the behaviour 
of definite groups of perithecia throughout one or more seasons under natural 
field conditions. 
For the carrying out of this work, " ascospore traps " were devised and 
placed over selected groups of perithecia under three different field conditions : 
first, in a young chestnut coppice ; second, in a chestnut orchard ; third, in 
a forest. The " ascospore traps " consisted of a glass slide slotted into a light 
wooden bracket which was permanently fixed in the bark above or below a 
group of perithecia. Seventy-six traps were placed on trees 4 to 8 inches in 
diameter, showing the perithecia in different stages of development. The 
observations extended over two years. 
It was found that expulsion of the spores begins in the spring with the first 
warm rain, and increases to a maximum as conditions become more favourable ; 
then follows a decline when lower temperatures prevail in the autumn, and it 
finally ceases in the cooler portions of the year, though there may be abundant 
rainfall. During 1913 the period of expulsion extended from the middle of 
March to the middle of September. There were nineteen rain periods during 
autumn, winter, and spring in 191 2-1 91 3 with no expulsion of ascospores, and 
in 1 91 3-1 91 4 there were eighteen rain periods with similar results. 
Perithecial pustules of this fungus show a remarkable power of spore pro- 
duction. This power is not exhausted during the course of a single season, 
and is as marked during the second season as during the first. This is due to 
the successive maturing of asci, to the successive maturing of perithecia, and 
of stromata throughout the season. — A.. B. 
Chrysanthemum fornieulatum {Bot. Mag. t. 8644). — Tenerife. Nat. Ord. 
Compo sitae, tribe Anthemideae. Shrublet, 2-5 feet high, glabrous and glaucous. 
Leaves up to 4 inches long, pinnatipartite ; segments linear. Heads 2 inches 
across, white. — G. H. 
Chrysanthemums, New. By Max Garmer {Rev. Hort. Feb. 16, 191 6 ; five 
illustrations). — Description of several new Chrysanthemums and of other 
novelties. — C. T. D. 
Cirrhopetalum concinnum var. purpureum {Bot. Mag. t. 8668). — Malay Penin- 
sula ; Nat. Ord. Orchidaceae, tribe Epidendreae. Herb, epiphytic. Pseudo- 
bulbs i-foliate. Leaves oblong, 3-5 inches long. Scapes 3 inches long, umbels 
many -flowered. Flowers J inch long, rose-purple. — G. H. 
Citrus Canker. By F. A. Wolf {Jour. Agr. Res. vol. vi. No. 2, April 1916, 
pp. 69-99; 4 plates, 8 figs.). — The causal organism {Pseudomonas Citri, Hasse) 
of this disease is studied very completely from its cultures on various media 
by the author, who finds that infection occurs through natural openings and 
wounds on the host plants. The bacteria take up a position between the cells 
and cause them to become hypertrophied. This is caused by the dissolution of 
the middle lamellae by enzymes. 
Besides Pseudomonas Citri, various fungi have been isolated from Citrus 
cankers. These include Phoma, Fusarium, and Gloeosporium, the first being 
especially active in the disintegration of the plant's tissues. This fungus has 
been given the name Phoma socia, n. sp., by the author. 
A short bibliography is appended. — A. B. 
Citrus Canker, III. By H. E. Stevens (U.S.A. Agr. Exp. Stn., Florida, 
Bull. 128, Nov. 1915, pp. 1-20 ; 6 figs.). — Citrus Canker is one of the worst of 
the plant diseases that have appeared in Florida, and has cost many thousands 
of dollars to eradicate it. 
It has been established by the author that the disease is caused by a bacterium, 
Pseudomonas Citri, Hasse, not by a fungus, as was formerly suspected. 
