654 EXPERIMENT STATION RECORD. 



resistant fungi becomes worthless for growing agricultural plants sub- 

 ject to it for a long series of years. On this account the greatest care 

 should be taken to avoid the spread of these parasites to land which is 

 now free from them. 



The black rot of cabbage and similar plants in Europe, H. A. 

 Hardinc4 {(''riitll. Jhilt. II. l\ir.^ 2. Al>f., G {lOUO), Xo. 10, pp. oOo-SlJ. 

 pis. ^,Ji(js. 2). — An account is given of the author's investigations in 

 Europe of the black rot of cabbage and similar plants, which has been 

 attributed to a l)acterial parasite, Pmudoin<>na>< compestrw. He reports 

 having observed the disease in the open held in about a dozen localities 

 in northwestern Europe. The organism was isolated, cultivated, and 

 comparisons made with the organism described by Smith and Russell 

 in this country. 



Infection experiments were conducted in pots in which the organisms 

 isolated from diseased cabbages in New York and in AYisconsin were 

 compared with the organism isolated from Swiss crucifers. At the 

 termination of the experiments the organisms were compared, and no 

 differences were noted Ijetween the bacteria derived from the different 

 .sources. 



Observations on a disease of plum trees, Duke of Bedford 

 and S. U. Pickering ( WoJjur?i E:rpt. Fruit Farm Rpt. 1900, p>i). 

 ^18-227). — In a previous report (E. S. R., 9, p. 761) a description is 

 given of a fungus disease which was proving fatal to standard plum 

 trees at Harpenden. The disease at that time was attributed to 

 Nectria dltissima, but subsequent investigations showed that this fun- 

 gus was not the primary cause of the disease. In 1898 -11 per cent 

 of the whole plantation had been killed b}^ the disease. The fungus 

 seems to spread very rapidly. Trees which failed to show any signs 

 of the disease M'hen examined in the winter, were badly attacked 

 before the following midsummer. From the tables given, it appears 

 that old trees, 9 years or more old, were the greatest sufferers. Sub- 

 sequent examinations in another locality of a disease which was 

 believed to be the same showed the trouble was due to Eutyp>eUa 

 prunastri. Successful inoculation experiments were conducted, which 

 produced s} mptoms very similar to those exhibited bv the trees at 

 Woburn Farm. While not affirming that the diseases are identical, 

 it is believed that the trees in each locality Avere suffering from the 

 same cause. A curious feature in connection with this disease was the 

 sudden disappearance of the disease in 1899. This sudden disappear- 

 ance is explained by the possibility that the fungus fruits only under 

 special climatic conditions, which were absent at this time. 



Fungus diseases of citrus trees in Australia and their treat- 

 ment, D, McAlfine {2£tlhi>urnt: Depart mcitf vf A<jrledture, 1899., 

 pp. 132., p)l^- ^^' — General descriptions and suggested methods of 

 treatment are given of the principal diseases of citrus trees occurring 



