PAPERS GIVING RUSTS OF NORTH AMERICA. 185 



collection at Philadelphia, either in the original autographic packets 

 or mounted. Of the additional species of rusts, two under the 

 genus Sphccria and two under Seiridimn, there are three represented 

 by specimens. 



The careful and conscientious work of Schweinitz is further 

 evident in the identification and naming of his material. This can 

 be shown by examination of the species which Schweinitz consid- 

 ered to be new, and to which he attached his initials. In the North 

 Carolina list there are 45 such species under the genera Aicidiiim, 

 Uredo (exclusive of the subgenera Albugo and Ustilago), Puccinia 

 and Gymnosporangkim, and of these only one was wholly misun- 

 derstood, nine are still accepted under the full names given by 

 Schweinitz, twenty-one still have the same specific name but are 

 placed under other genera and fourteen only have the name wholly 

 suppressed under synonymy. In the North American list there are 

 88 names followed by the initials of Schweinitz under the genera 

 Cceoma '(exclusive of the subgenera Albugo and Ustilago), Puc- 

 cinia, Phragmidium, Gymnosporaugium and Podisoina. Only four 

 of these species were misunderstood and erroneously placed, while 

 twelve are still accepted as named, twenty-four still retain their 

 specific names under other genera, and forty-eight have the W'hole 

 name relegated to synonymy. The discarding of over half of the 

 new names found in the later work is largely due to Schweinitz's 

 replacement of earlier names by others conforming to Link's new 

 methods, as already explained, which made them untenable accord- 

 ing to the present requirements of priority. The above showing is 

 as good as can be found in most lists of rusts by recent mycologists, 

 so rapid are the mutations in nomenclature of this group of fungi. 

 In general it shows that Schweinitz made comparatively few mis- 

 takes in the identification of his material, and in naming tried very 

 commendably to follow the most progressive and authoritative 

 methods as then understood. At the present time the two or three 

 dissimilar stages which many rusts exhibit are included under one 

 name, while formerly they were placed under separate genera. This 

 in large part accounts for the 125 numbers in Schweinitz's North 

 American list, now known or believed to represent rusts, having 

 shrunken to 90 species as at present classified. 



