[Vol. 2 



628 ANNALS OF THE MISSOURI BOTANICAL GARDEN 



resulted in the publication of other species by various authors, 

 whose descriptions contrast sharply with that of Woronin in 

 giving little weight to the morphological characters of the 

 fungus under consideration, but extended description of the 

 form and color of the gall of a particular collection, with pass- 

 ing reference to the occurrence of the fungus upon a hitherto 

 unpublished host. In case of the galls, the descriptions usually 

 fail to state what other forms besides the one mentioned the 

 galls may have on other organs of the new host and likewise 

 omit mention of the different forms they may have at other 

 times in the year than the particular time at which the type 

 collection was made. Woronin 's description of E. Vaccinii 

 was based upon field observations extended through two sea- 

 sons, during which more than a thousand specimens were col- 

 lected. He gives one double page colored plate to show the 

 various types of galls produced by the different organs of 

 V actinium vitis-idaea. 



Plate 21 is a photographic reproduction, reduced one-fifth, 

 of Woronin 's colored plate; it shows the forms of galls as 

 determined by the particular organ of the host, Vaccinium 

 vitis-idaea, which makes hypertrophic response to local stimu- 

 lation by the parasitic fungus. A local change of color from 

 green to some shade of red is common in plant portions in- 

 fested with Exobasidium. In the photographic reproduction 

 of Woronin 's plate the reddened areas of the original appear 

 light colored. In fig. 1, the left side of the uppermost leaf 

 was attacked by the fungus, producing what I term a leaf 

 spot gall. The affected region of the leaf is reddened on the 

 upper side and bears the fructification which may be felty or 

 scurfy on the under side ; this leaf is not distorted much in 

 form and thickness. 



Figures 2-9 present leaf galls, reddened on the upper side 

 of the leaf and distorted and thickened by hypertrophic 

 growth so as to become more or less concave with respect to 

 the upper surface. I designate this form of gall as leaf 

 concavity. 



Figures 10-17 illustrate shoot galls, in the production of 

 which, stems of the current season's growth have been greatly 



