544 EXPERIMENT STATION RECORD. 



Chestnut blight resistance, R. T. Morris {Jour. Heredity, 5 (1914), ^o. 1, 

 pp. 26-29, figs. 2). — The author reports that in 1905 in a chestnut forest in 

 Connecticut there were about 5,000 old American chestnut trees, a few chin- 

 quapins (Castanea pumila), and two saplings of 0. mollissima, the Chinese 

 chestnut. When it became evident that the chestnut bark disease was threaten- 

 ing the American chestnut trees an attempt was made to find blight resistant 

 individuals, and plantings were made of 26 different kinds. These included 

 the American species as well as a considerable number of others introduced 

 from Europe and Asia. There were also a number of grafted varieties of differ- 

 ent sorts. 



In 1913 every one of the old American chestnut trees had become blighted 

 and had been removed, and the younger trees and stump shoots are said to 

 be practically all dead or dying with the blight. The various grafted varieties 

 of European and Asiatic chestnuts showed different degrees of resistance to 

 blight. This was also true of the seedlings of European and Asiatic varieties. 

 None of them appeared to be quite as susceptible to the disease as the American 

 chestnut, but most were affected and ultimately died. The Korean chestnuts 

 and chestnuts from the Aomori region in Japan resisted the blight almost com- 

 pletely until they were about six years old. Since that time they have shown 

 a tendency to attack, but resist the fungus somewhat better than the American 

 chestnut. The Korean and Japanese chestnuts when grafted on American 

 chestnut sprouts all blighted in their second or third year, seeming to indicate 

 that the sap from the American chestnut had made them susceptible to the 

 fungus. A -hybrid between the American sweet chestnut and the chinquapin 

 blighted when about 8 years old. None of the American species of the chin- 

 quapin, varying from 5 to 13 years, has blighted, with the exception of 2 limbs, 

 which were injured by the falling of another tree upon them. None of the 

 specimens of C. alnifolia nor C. mollisswui has thus far shown any indication 

 of bUght. 



A number of hybrids between the different species have been made and are 

 being tested for possible resistance. While making these hybrids the author 

 discovered that parthenogenesis occurs among the Castaneas, and incidentally 

 it was found that the same takes place in a number of species of walnut and 

 hickory. 



Injury by oak mildew, Nikodem (Centhl. Gesam. Forstw,, 39 {1913), No. 10, 

 pp. 438-440). — ^A brief account is given of the progress of oak mildew in 

 Croatia, which increased from 1907 to 1911, when it became much less general. 

 A sudden renewal of activity in 1912 and since has been noted in connection 

 with the presence and increase of a leaf wasp {Emphytus flliformis), which is 

 discussed in this connection. 



Pustule formation on Hevea brasiliensis, J. Kuijpeb {Rec. Trav. Bot. 

 N^erland., 10 {1913), No. 2, pp. 137-146, pi. 1, figs. 7).— The author describes 

 an abnormal condition of the cortex, observed on the lower portions of two 

 young rubber trees, and thought to be related to that previously mentioned by 

 Fetch (E. S. R., 28, p. 246). Almost no latex is obtained from the roughened 

 portions. The pustules are said to be independent of subcortical buds or in- 

 juries so far as known, and to show no connection with the deeper portions 

 of the wood. 



Bark rusts of Juniperus virginiana, C. Hartley {Phytopathology, 3 (1913), 

 No. 4, p. 249). — According to the author, the bark rusts of cedar in the 

 vicinity of Washington, D. C, are mostly due to Oymnosporcmgium clavipes, G. 

 nidus avis, and G. effusiim. 



An epidemic of needle diseases in Idaho and western Montana, J. R. Weib 

 (Phytopathology, 3 (1913), No, 4, pp. 252, 253).— The author describes Lopho- 



