Mabch 18, 1910] 



SCIENCE 



437 



limits of the recurved spindle fibers, but it is not 



formed out of them. 



Two Trunk Diseases of the Willow Oak (Quercus 



phellos) : Hermann von Schbenk, St. Louis, 



Mo. 



The vcillow oak is attacked by two polyporoid 

 fungi which destroy the heart wood. No such 

 diseases have hitherto been described, and the 

 discovery at this time was due to the unusual 

 hurricane which destroyed vast numbers of trees 

 in the southern states during the past fall. 



A description of the cause of the disease, the 

 manner in which the trees are attacked and de- 

 stroyed and the distribvition form the chief topics 

 of the paper. 

 A Trunk Disease of the Osage Orange (Toxylon 



pomiferum) : Hermann von Schbenk, St. 



Louis, Mo. 



The osage orange has hitherto been considered 

 as practically immune from fungus diseases. The 

 wood of this tree is very indestructible when used 

 for structural purposes, and so far as known, no 

 fungus ever attacks the heart wood. The present 

 paper describes the finding of fungus disease of 

 the heart wood, which occurs in living trees. This 

 disease is of particular interest in view of the 

 geologic age of the genus, and furthermore in view 

 of the fact that this is the first case of a trunk 

 disease of this species. 

 Studies on the Toxicology of Diplodia zece: 



Howard S. Reed, Agricultural Experiment Sta- 

 tion, Blackburg, Virginia. 



A brief examination of the literature dealing 

 with the etiology of pellagra shows great diversity 

 of opinion as to the identity of the fungi held 

 responsible for the deleterious property of the 

 affected maize. In this connection attention is 

 called to the recent spread in this country of 

 Diplodia zece. This fungus became conspicuous 

 as the cause of wide-spread injury to maize almost 

 simultaneously with the appearance of pellagra. 

 It is also present in European countries where 

 pellagra is found. Recent studies have shown that 

 the fungus lives parasitically upon the growing 

 maize as well as saprophytically upon the mature 

 grain. 



The author has in progress chemical and physi- 

 ological experiments upon the properties of maize 

 infected with Diplodia. The chemical substances 

 isolated to date have similarity to those isolated 

 by Lombroso. Physiological experiments have 

 shown that the infected maize is toxic to small 

 animals. 



Some Notes on Sclerotinia fructigeim: James B. 



Pollock, LTniversity of Michigan. 



Aderhold suggested in 1905 that the species of 

 Sclerotinia commonly attacking stone fruits in the 

 United States was S. oinerea and not S. fructi- 

 gena, as had been assumed. He based his opinion 

 on several facts: the color of the tufts of macro- 

 nidia on the attacked fruits, the size of the 

 conidia, the occurrence in Europe of 8. cinerea 

 chiefly on stone fruits and of 8. frucligena on 

 pome fruits, and lastly on the size of asci and 

 ascospores which Norton described in 1902. 



Studies were made on material collected at Ann 

 Arbor and Lansing, Michigan, and this was com- 

 pared with the reports of various workers in 

 Europe and the United States. The conclusions 

 reached are: 



Norton's measurements for asci and ascospores 

 are probably incorrect. The apothecia found in 

 Michigan as well as in other parts of the United 

 States agree very closely with those of Sclerotinia 

 fruotigena as found in Europe. There is a wide 

 range in the size of the macroconidia, especially 

 on artificial media, and as found in nature they 

 are generally smaller in the United States than 

 in Europe. 



In the United States the species occurs more 

 commonly on stone fruits, and in Europe more 

 commonly on pome fruits. 



Sclerotinia fructicola (Winter) Rehm is in all 

 probability the same species as Sclerotinia fructi- 

 gena (Pers.) Norton. 



The Present Status of the Cytology of the Rusts: 

 E. W. OuvE, South Dakota State College of 

 Agriculture and Mechanic Arts. 

 Only fourteen species of rusts have contributed 

 so far toward a solution of the problem as to the 

 sexual cell fusions in this group of fungi. Of this 

 number, nine were secial forms, five telial. Black- 

 man himself leaves his four telial species in a 

 doubtful condition; and the writer's work on the 

 development of the fecidium cup forms casts doubt 

 on the interpretation of both Christman and 

 Blackman as to the four cup forms which they 

 studied; thus leaving only six species in a pre- 

 sumably stable condition as to the method of 

 sexual union. Of these six species, three — Gymno- 

 conia intersiitialis, Phragmidium speoiosum and 

 Phragmidium violaceum, belong to the diffuse 

 ca;oma type of secidium; two — Phragmidium po- 

 tentillcE-canadensis and Triphragmium ulmarieoe, 

 to the primary uredo type, and one — Puccinia, 

 transformans, to the micro-puceinia type. 



