December 27, 1912] 



SCIENCE 



913 



Taking all the evidence into consideration, 

 we can not see why the Splusria gyrosa of 

 America discussed by Schweinitz does not as 

 certainly relate to the present Endothia gyrosa 

 of Europe and America as does the Bphceria 

 gyrosa of Europe discussed by Pries, on which 

 no one raises a question. From Schweinitz's 

 description of 8. gyrosa and 8. radicalis we 

 believe he either had both of the species now 

 recognized here, or else he had the Cytospora 

 (Endothiella) and the mature stages of one, 

 and described these as two species. In the 

 latter ease the evidence, as shown by the 

 Curtis drawing, is more in favor of these 

 descriptions applying to the narrowly-oval 

 than to the linear-spored form. We think, 

 however, that the simplest and best solution, 

 until positive proof to the contrary is pre- 

 sented, is to decide that Schweinitz had both 

 species. From their indistinguishable Cyto- 

 spora stage, which was the stage usually found, 

 it was natural enough that in time European 

 botanists should place 8. radicalis and 8. 

 gyrosa together in one species, especially if 

 the former does not occur in Europe. 



Having established the identity of our nar- 

 rowly-oval spored form, what about its appear- 

 ance in cultures and its action when inocu- 

 lated into living hosts? Cultures from vari- 

 ous localities in the south, from both chestnut 

 and oak, have been under observation for over 

 nine months, and all of these present identical 

 characters that distinguish them rather easily 

 from the true chestnut blight fungus when 

 grown under the same conditions. We give 

 these distinguishing characters briefly under 

 our discussion of the latter fungus. 



Inoculation tests were likewise made on 

 seedling and sprout growths of both oak and 

 chestnut, from cultures of Endothia gyrosa 

 from both oak and chestnut, and these uni- 

 formly gave different results from the true 

 blight fungus when inoculated under similar 

 conditions. In other words, in no case did we 

 succeed in producing very evident cankers 

 from this fungus, and in most cases the in- 

 oculations were absolute failures. Yet there 

 were indications of a semi-parasitic nature 



with a few inoculations made under condi- 

 tions rather unfavorable to the host. The 

 fungus is evidently largely a saprophyte, but 

 with slight parasitic tendencies. 



This fungus has so far been found on chest- 

 nut and oak in this country from North Caro- 

 lina to southern Pennsylvania. It also occurs 

 on these hosts in Prance, Italy, Switzerland 

 and apparently in several other European 

 countries. Saccardo gives other hosts and a 

 wider distribution, but an examination of 

 asco-material is necessary to verify these. 



3. The Broadly-oval 8pored Endothia, E. 

 gyrosa var. parasitica (Murr.). — This is the 

 true chestnut blight of the northeastern 

 United States. Originally described as a new 

 species, Diaporthe parasitica, by Murrill, it 

 has since been called Valsonectria parasitica 

 by Eehm and Endothia parasitica by the An- 

 dersons. Other botanists already mentioned 

 do not distinguish it from the Endothia 

 gyrosa just discussed. All botanists who have 

 recently made a thorough study of it, however, 

 seem to agree that it belongs more properly 

 under the genus Endothia, as first suggested 

 by Parlow and the writer, than under Dia- 

 porthe. Prom our own study we can not 

 agree with those who think it identical mor- 

 phologically with Endothia gyrosa, yet we be- 

 lieve it agrees with that species so closely that 

 it belongs under it as a variety rather than 

 ranks as a distinct species, as considered by 

 the Andersons. Hence the name given in the 

 heading. 



The ascospores vary from narrowly- to 

 broadly-oval, sometimes tapering somewhat to 

 one or both ends, have a distinct septum at 

 which they are sometimes slightly constricted, 

 and are chiefly 6-10 /x long by 2.75-5 /x wide. 

 Those of 8. gyrosa, as given above, are 6-9 ^u, 

 long by 2-3.5 fi wide, thus showing the chief 

 difference to be in their width. Cultures of 

 this fungus as compared with those of En- 

 dothia gyrosa grown on potato, lima bean and 

 oat agars, give certain constant differences 

 most strikingly shown perhaps when young on 

 the potato and when old on the oat agar. 

 These differences, briefly pointed out, are as 

 follows : 



