Pebkuary 22, 1907] 



SCIENCE 



305 



recent outbreak in California. The next day, 

 after identifying- tlie fungus, in the orchards 

 at Suisun, Cal., the serious character of the 

 outbreak of this disease became evident. All 

 over the one-year tveigs of the peach trees the 

 small spots of the fungus were apparent. 

 Many of the spots were necrotic and exuded 

 gum at that early date. Scarcely an inch of 

 the sound twig- growth but carried one or more 

 spots. Furthermore, the fungus had attacked 

 the buds and killed and ruined by far the 

 larger proportion of them, in many cases from 

 90 to 95 per cent, were already dead. On 

 jarring- the trees a shower of these dead 

 buds fell to the ground, others were glued 

 fast to the twigs by the g-ummy exudate. 

 As the season advanced and the buds opened 

 into blossoms the scarcity of the latter became 

 more and more apparent. The spots on the 

 twigs and the diseased buds exuded drops of 

 gum which frequently ran down the twigs or 

 dropped to the ground. 



Spraying with Bordeaux mixture was at 

 once suggested as a promising remedy, but the 

 writer was informed that this had been tried 

 and had proved to be a failure. Upon further 

 questioning and an examination of the sprayed 

 trees it was found that the treatment had 

 been made some two weeks before, while the 

 spots were in many cases older. The sugges- 

 tion was then immediately made that spraying 

 would have to be done in the fall or early 

 winter, considerably ahead of the first ap- 

 pearance of the new infections. 



This proved to be the key to the treatment 

 of the disease. Three growers at Suisun, J. 

 S. Brown, Geo. Eeed and J. S. Chadbourne, 

 sprayed blocks of trees in December, 1905, 

 with Bordeaux mixture; in one case where the 

 disease had been unusually severe the year 

 before the trees had been sprayed a second 

 time about January 15, 1906. Upon exam- 

 ining them late in March there was to be 

 found scarcely a single diseased bud upon the 

 sprayed trees, and where one was found, it 

 was on a twig not reached by the spray. The 

 contrast between the sprayed and unsprayed 

 trees was very striking, the disease being even 

 more severe in 1906 than in previous years. 

 I was informed that the good results became 



even more noticeable as the fruit was har- 

 vested, immense crops of fine fruit being 

 picked from the treated blocks, while adjacent 

 orchards, often of the same variety, separated 

 only by a wire fence, were practically failures. 

 The crop of fruit in one case where the 

 trees had been thoroughly treated, reached 42 

 tons from 100 trees, and in another case 400 

 trees yielded 100 tons of fruit, and similar 

 productiveness occurred with other varieties. 



The disease scarcely ever kills the tree, ex- 

 cept possibly a young one, but it kills a great 

 many of the branches, cripples the tree and 

 ruins its productiveness. 



Further experiments are in progress this 

 year, beginning early in November, 1906, to 

 test more definitely the most desirable dates 

 for spraying, number of treatments, strength 

 of Bordeaux mixture and the possibilities of 

 using other sprays, especially the lime-sulphur 

 preparation. This lime-sulphur spraying is 

 done quite regularly in many California or- 

 chards, as well as in certain sections of the 

 eastern states to prevent the San Jose scale. 

 If this spray proves effective it may only be 

 necessary to change the date from late winter 

 or early spring to fall or early winter and 

 thus prevent both the scale and the peach 

 blight. 



This Coryneum occurs not only on the 

 peach, but is seriously injurious on the almond 

 and apricot as well in California. It is known 

 to be an important factor in most of the recent 

 failures in the productiveness of these or- 

 chards. Experiments are also in progress in 

 the treatment of the disease on these fruits. 



In answer to a question, Mr. Waite said 

 there was little doubt that the blight existed 

 in Oregon and Washing-ton, though it had not 

 been definitely observed. 



The second paper, by Mr. John W. Titcomb, 

 was entitled ' Some Work of the Beaver.' 

 While engaged in field work Mr. Titcomb 

 visited Maskinonge County in the province 

 of Quebec and during the month of June dis- 

 covered on Lake Madam Henry a series of 

 four freshly-built beaver dams. The upper 

 one raised the lake some two and a half to 

 three feet, overflowing quite a large area of 

 lowland at the head of the lake where the 



