502 



SCIENCE. 



[X. S. Vol. XXI. Xo. 53-). 



or shriveled, the soft rot was sure to be 

 found on cutting down the tree and remov- 

 ing the close-wrapped leaf bases. No at- 

 tempt has yet been made to produce the 

 disease by pure cultures. 



Diseased trees should be felled and the 

 terminal bud burned or properly disin- 

 fected with sulphate of copper. Only the 

 most energetic action is likely to avail. 



Some Diseases of Lohlolly Pine Timber: 

 Dr. Hermann von Schrenk, Depart- 

 ment of Agriculture. 

 The wood of the loblolly pine when still 

 in the living tree is destroyed by several 

 fungi, notably Trametes pini and I'olyponis 

 Schiceinitzii. After the timber is cut from 

 the tree, it is very susceptible, particularly 

 in southern climates, to fungus attacks, and 

 is probably the least resistant of all Amer- 

 ican woods. A number of fungi grow on 

 the outside of the timber, notably Schizo- 

 phyllum commune and several Thele- 

 phoracefB. These, however, do not attack 

 the wood fibers, but grow on the sugar, 

 starch or exuding resins. The worst enemy 

 of the loblolly pine timber is Lenzites 

 septaria, which causes the brown rot. The 

 description of the various forms of fruiting 

 bodies of this fungi were given, and an 

 account of the experiments which were 

 made during the last year to test the sus- 

 ceptibility of this timber, when cut dur- 

 ing different months of the year. It was 

 show^n that by proper piling, the attacks of 

 this fungus ought to be prevented for 

 periods of at least twelve months. 



Bacterial Infection by Way of the Stomata 

 in Black Spot of the Plum: Dr. Erwin 

 P. Smith, Department of Agriculture. 

 ^By title.) 



Experiments were continued during the 

 summer of 1904 with the bacterial black 

 spot of the plum, and numerous infections 

 by way of the stomata were obtained on 



leaves and green fruits by simply spraying 

 upon the tree, agar-cultures of P. pruni 

 dissolved in sterile water. This was done 

 during a damp still evening, in which sev- 

 eral light showers occurred. The spots 

 were visible at the end of seven days and 

 continued to increase for several weeks in 

 the typical manner. ^Microtome sections in 

 early stages of the spots show abundant 

 bacterial occupation, beginning in the sub- 

 stomatic chamber. The organism was also 

 recovered from the spots by means of agar 

 poured plates in pure culture. A neigh- 

 boring tree inoculated at the same time 

 and in the same way, but with a different 

 yelloAV organism, never showed any results 

 of this copious inoculation. Neither did 

 any spots develop on a second check tree. 

 The disease appears to be one of meriste- 

 matic tissues. No spots were obtained on 

 full-grown green plums, inoculated two or 

 three weeks prior to their ripening, al- 

 though numerous attempts were made un- 

 der what appeared to be very favorable 

 conditions. 



Burrill's Bacterial Disease of Broom Corn 

 (illustrated) : Dr. Erwin P. Smith and 

 Miss Plorence Hedges, Department of 

 Agriculture. 



In the summer of 1904, on one of the 

 Agricultural Department farms in Wash- 

 ington, D. C, this disease was observed in 

 such abundance and with such tj'pical char- 

 acteristics as to remove all doubt as to its 

 origin. The elongating red-brown bL tclies 

 were extremely numerous and fused 

 readily, causing the death of many large 

 leaves. The disease began on the lower 

 leaves; but by the end of September it had 

 reached the top of the plants (twelve feet) 

 and had destroyed all leaves on the lower 

 six feet, and badly spotted the remainder. 

 A microscopic examination of various spots 

 showed a bacterial focus to be present in 

 each one. Poured plates made from these 



