February 22, 1907] 



SCIENCE 



291 



tematic position is between the Agaricaceae 

 and the Polyporacese. 



Ascigerous Forms of GlcBOsporium a/iid 



Colletotrichum: C. L. Shear and Anna 



K. Wood, Bureau of Plant Industry. 



Stoneman, Clinton, Spaulding, von 



Sehrenk and Sheldon have already given 



the life histories of a number of forms. 



Klebahn has also reported ascigerous stages 



of two species which have been referred to 



Glceosporium, but which are evidently not 



congeneric with the organisms studied by 



the other authors mentioned, and by the 



present writers. 



Forms from eight different hosts have 

 been grown in pure cultures and both coni- 

 dial and ascigerous perithecia produced. 

 The forms studied occurred upon the fol- 

 lowing hosts: grape {Vitis sp.), apple 

 '^Pyrus malum), cranberry '{Vaccinium 

 mMcrocarpum) , rubber plant (Ficus elas- 

 tica), locust {Gleditschia triacanthus) , 

 Ginkgo biloha, cotton (Gossypium sp.) and 

 bean {Phaseolus vulgaris). 



The form on the apple has been grown 

 several times before. In none of the other 

 cases mentioned has the ascigerous form 

 been heretofore produced, as far as known. 

 The forms investigated can not be speci- 

 fically segregated by morphological char- 

 acters, and for the present are regarded as 

 varieties of a single species. The asciger- 

 ous form has been found upon its host 

 under natural conditions in only two cases, 

 viz., on the apple and Ficus elastica. The 

 presence of paraphyses has been reported 

 by Sheldon. Organs sometimes occur 

 which, if not aborted or mal-formed asci, 

 may be called periphyses. The factors 

 which determine the production of the 

 ascigerous fructifications are still doubtful. 

 Having once obtained a race or individual 

 which produces asci, it can be successfully 

 grown on various media and under various 

 conditions. The mycelium, having entered 



the tissues of its host, has the power of re- 

 maining dormant for an indefinite period. 



A New Chrysanthemum Disease— The Bay 

 Blight: Professor F. L. Stevens, North 

 Carolina College of Agriculture and 

 Mechanic Arts. 



Specimens of this disease were first re- 

 ceived from Fayetteville, N. C. It was 

 later found in Raleigh. Its most con- 

 spicuous appearance is as a blight of the 

 ray flowers of the head. It also occurs in 

 the stems. Examination showed a fungus 

 constantly present in the diseased part. 

 This was repeatedly isolated by plate cul- 

 ture; its culture characters were studied 

 on various media ; and its temperature and 

 acid relation were determined. Inocula- 

 tions were then made upon chrysanthe- 

 mums under various conditions, producing 

 typical cases of disease. The organism 

 was recovered from these artificially inocu- 

 lated blossoms and proved identical with 

 that found in eases of natural infection. 

 The fungus belongs to the genus Ascochyta, 

 apparently a new species for which a tech- 

 nical description is provided. 



A Potato Leaf-ilotch Fungus New to 

 America: Professor L. R. Jones, Uni- 

 versity of Vermont. 



The fungus in question is Cercospora 

 concors, first described by Dr. Robert 

 Caspary in 1854, from collections made in 

 the vicinity of Berlin. Since that date it 

 has been observed with increasing fre- 

 quency in Europe, proving most serious in 

 the northern sections. The author has 

 found it in Vermont at three well-separated 

 stations and in three seasons, the first col- 

 lection having been made in 1902. It has 

 occurred in each case in old gardens and the 

 indications are that it is a well-established 

 parasite on the cultivated potato and prob- 

 ably widely distributed in the longer 

 settled parts of the northeastern states and 



