94 fournal oj Mycology [Vol.13 



careful citation, admirable descriptions, host lists, etc., as well 

 as the synoptic keys to the families, the genera, and the species, 

 are all to be most highly commended. 



This publication deals with minute plants and as has been 

 well said they must be studied with a corresponding minutia. 

 We may regret it but it was inevitable — the simplicity of the 

 old order of things has disappeared. To know the Rusts is to 

 know their life histories, their spore forms, the structure of the 

 sorus, and the various morphological characters — all of which, 

 together with apparent phylogenetic relationships, have been em- 

 ployed by the author in constructing this exhaustive monograph, 

 epoch making and destined to become classic. 



AN APPLE ROT DUE TO VOLUTELLA. 



F. L. STEVENS AND J. G. HALL. 

 N. C. Agr. Exp. Station. 



A black rot of apples closely imitating in appearance that 

 caused by Sphaeropsis. but differing from the sphaeropsis rot 

 in several details, has been observed frequently in various sec- 

 tions of this State, on native apples and on apples shipped into 

 the State from a distance. 



In general appearance the disease consists of a rotten black 

 spot upon the fruit. The central and older portions of the de- 

 cayed region are of an intense coal black color. The younger 

 region of the spot, its outer border, a zone about 14 mm. in 

 width, is brownish. 



Close inspection reveals the presence of slightly elevated 

 pimple-like places in the cuticle. These are found to within 

 3 or 4 mm. of the edge of the spot, and become larger and 

 more pronounced as the center of the spot is approached. Indeed 

 the black color of the spot is due to the thick setting of these 

 black pimples all over its surface. In many instances unless 

 the spot be very old no other development is seen, and the dis- 

 ease might readily be considered to be the ordinary black roi 

 caused by Sphaeropsis, and doubtless often passes for it. In 

 older spots however, the pimples are seen to have broken through 

 the cuticle of the apple, and each pimple appears as a small 

 wart-like excresence, and a good lens shows that it is thickly 

 beset with stiff black hairs. These hairs constitute the distinctive 

 character of this disease, and serve to separate it with ease and 

 certainty from the Sphaeropsis rot, provided the rot has devel- 

 oped far enough to exhil^it this character. 



On slicing the apple open it is seen that the zone most re- 

 cently invaded is brownish, while all the older portion is black. 



