May, 1920 J PATHOLOGY 233 



lapses for u anl of plant nutriment. When the main arms or sub-leaders only are affected, the 

 stem being healthy, the case is not so serious, because corrugations of the virulent form 

 ran bring about the destruction of individual branches only. Scientific pruning will often 

 obviate the production of those undesirable sections or replace them by others of m re 

 befitting character." — D. Reddick. 



L637. Fragoso, Romualdo GonzIlez. La ''antracnosis" o "rabia" del guisante iAsco- 

 chyta Pisi Lib.). [Anthracnose or rabies of peas.] Bol. It. Soc. Espafiola Hist. Nat. 19: 189- 

 196. PI. 6 (colored), fig. IS. 1919. — Author studies a severe epiphytotic of anthracnose on 

 peas encountered in markets of Madrid during the latter part of last winter and early spring. 

 Causal organism is identified as Ascochyla pisi. It is compared critically with Phyllosticta 

 rabciei. — Discusses reported hibernation of fungus and believes such noi to occur but that 

 the fungus is propagated by pycnidia and conidia remaining on the ground in dead parts of the 

 plant, this infecting next crop. — Contrary to some authors the fungus penetrates and attacks 

 the seeds in the pod. Completing often the destruction begun by the Ascochyla the author 

 finds commonly two fungi, Cladosporium pisi, and a form of Macrosporium commune which 

 is published as new (M. commune f. Pisi), illustrated and described fully. Differs from 

 type in having conidiophores up to 70 x 7 m or even 125 x 7 y., apically inflated, 15-56 x 9-21 /x. 

 Author discusses briefly methods of treatment. — 0. E. Jennings. 



1638. Kirk, T. W. Control of brown-rot of stone fruits: The past season's experiments. 

 New Zealand Jour. Agric. 18:272-284. 1919.— It is stated that all the preparations used 

 failed to prevent the disease entirely. Judicious thinning of fruits and the destruction of 

 infected fruits is advised, to minimize the possibility of infection. — E. R. Hodson. 



1639. Klebahn, H. Impfversuche mit pfropfbastarden. [Infection experiments with 

 graft hybrids.] Flora 111-112:418-430. 9 fig. 1918. — In the experiments Solanum lycoper- 

 sicvm proved susceptible to the attacks of Seploria lycopersici while S. nigrum is immune. 

 S. tubingense, which has epidermal tissue of S. lycopersicum and inner tissue of S. nigrum, 

 proved highly resistant. Mycelium was found in the leaf but very small flecks were produced 

 and the fungus did not fruit. — Solanum proteus, having a double layer of tomato tissue on 

 the outside with additional areas of tomato tissue scattered promiscuously, proved sus- 

 ceptible. Pycnidia were formed, but were found most abundantly in the vicinity of tissue 

 recognizable as tomato tissue (oxalate cells). — -S. koelreuterianum, epidermis cf S. nigrum, 

 inner tissue of tomato, proved susceptible. Large blackish spots were formed on which 

 pycnidia appeared later. Failure of the epidermal tissues to protect is attributed to the 

 fact that infection is stomatal. — S. gaerlnerianum, having a double layer of nightshade tissue 

 about tomato tissue and with additional areas of nightshade tissue scattered promiscuously, 

 proved immune in experiments performed in 1913. In later experiments some spots were 

 formed on which pycnidia appeared. The pycnidia were always closely associated with 

 tissue recognizable as tomato tissue. — S. dariuinianum, having epidermis and inner tissue 

 of S. nigrum separated hy areas of tissue representing somatic cell fusions of the two species, 

 is like S. koelreuterianum. — S. lycopersicum gigas, a giant form, among other things having 

 chromosomes double the usual number, is as susceptible as the common tomato. — Clado- 

 sporium fulvum acted like Septoria on those chimeras tested. — D. Reddick. 



1640. Kotila, J. E. Frost injury of potato tubers. Rept. Michigan Acad. Sci. 20:451- 

 460. 1918. — Tubers kept at room temperature for 5 days after being subjected to a tempera- 

 ture of — 13°-17 e C. for 3-4 hours showed necrosis injury; when exposed to temperature of 

 — 13° to — 17° for five or more hours, less injury than when exposure was for 3 to 4 hours; and 

 when exposed to ■ — 5° to — 11° for 24 hours they showed darkening of the tissues. Exposure of 

 tubers to a temperature of — 13° to — 17° for 4 hours killed the sprouts. [See Bot. Absts. 2, 

 Entry 863.] — Charles R. Stevenson. 



1641. Laidlow, W., and C. C. Brittlebank. Black spot and leaf curl. Jour. Dept. 

 Agric. Victoria 16: 479-488. 11 fig. 1918. — Experiments for the control of leaf curl of peach 

 and apricot (Exoascus deformans) show that spraying with verdigris (3 pounds in 40 gallons 



