1142 EXPERIMENT STATION RECORD. 



ollu'r tit'cs. liivestijiiil ii)ii sliowfd lliai most of it is fiiiis('<l l>y various species 

 of uiusliroouis, the one most iiarticuiariy concerned being the lioney agaric 

 (Agaricus mcllcus). 



For the prevention of injury, the clearing of lauds, in which all roots and 

 stumps should be removed, and the draining and cultivation of the newly 

 cleared lauds are recommended. When trees are found slightly affected they 

 can be protected to some extent by uncovering the roots, removing the diseased 

 jtortions. and spraying the sound parts with fungicides. 



Observations on the relation of wound parasites to the heartwood of 

 the affected tree, P. Spaui.ding (Abs. in Science, n. scr., 2!) (JHO!)), Nd. 7J7, 

 p. 272). — While studying various wood-rotting fungi, the author has noted an 

 apparent relation between the wound parasites and the? heartwood of diseased 

 trees, A striking instance of this was that of Fomcs inbis occurring on sassafras 

 trees. In every case examined this fungus was found attacking the trees only 

 in wounds where the heartwood was exposed by some injury. F. igniarius, 

 studied upou the beech, was found to occur in a similar manner. Hundreds of 

 blazed beech trees have been examined, but in not a single instance was the 

 fungus found growing where the wound only extended into the sapwood. On 

 the other hand, it was constantly found in wounds extending into the heartwood. 

 The fungus rolystictus versicolor on catalpa and F. fraxinopliilus on the white 

 ash can be traced to the heartwood through dead stubs or wounds. In a 

 similar way vou Schrenk has called attention to the fact that F. rimosus, which 

 attacks the heartwood of black locust, enters either through the dead stubs or 

 through insect burrows. 



These investigations seem to indicate that the heartwood must be exposed 

 before these fungi are capable of attacking the hosts. 



Rusts on the leaves of bamboos, S. Kusano {Bui. Col. Agr. Tokyo Imp. 

 Univ., 8 {1908), Isio. 1, pp. 37-50, pi. 1, fig. 1). — A description is given of 5 species 

 of Pucciuia known to occur on bamboos in Japan, the species being P. phyllos- 

 tachydis, P. sasw, P. kiisanoi, P. kusanoi azvma, and P. longicornis. Notes are 

 included on the distribution, economic relationship, and some of the biological 

 characters of the different species. 



A new disease of oaks, A. Fiori {Bui. R. Soc. Toscana Ort., 3. scr., 13 {1908), 

 Ao. 9, pp. 266-268). — A description is given of the mildew of oaks, which was 

 very prevalent in the oidium stage in Europe during 1908. The author thinks 

 that it is probably Microsphcera qucrcina, although the fruiting stage has not 

 been found. 



Oak mildew in the southwest of France, Gard {Jour. Bot. [Pat'ts], 21 

 {1908), No. 10, pp. 253-256). — An account is given of the occurrence of mildew 

 on oak trees in the southwest of France during the summer and autumn of 

 1908. The species Quercus tozza seemed most susceptible, although others were 

 subject to attack. The most injury was done on the yoiuig trees, particularly 

 where they were grown as coppice. The season seemed to have been especially 

 favorable to the development of mildews, as the author reports mildews abun- 

 dant on a number of other sjiecies of i)lants. 



Biology of the chrysanthemum rust, S. Kusano {Bui. Col. Agr. Tokyo Imp. 

 Univ., 8 {1908), ISlo. 1, pp. 27-36, fig. 1). — A study has been made of the rusts 

 which are known to attack various species of chrysanthemums in Japan, par- 

 ticular attention being paid to the black rust {Pucrinia chrysanthemi) , the 

 white rust (P. horiana), and the brown rust {Uredo autumnali.s). 



The author states that there is some (luestion as to the specific name of the 

 first species as well as the host plants attacked. The white rust is of compara- 

 tively recent scientific knowledge, although it is said to have been known by 

 gardeners for a considerable time. It proves very destructive, particularly on 



