OP ARTS AND SCIENCES. 69 



sioa of several species by older writers. Rather than favor that 

 method — if one may say so — of forcing priority, I should prefer to 

 give up the substitution of all old Uredo names, except, possibly, in the 

 case of species now referred to Uromyces. 



To make a long story short, I am of the opinion that in naming 



Uredlnece we should go back to the oldest specific name given to the 

 teleutosporic form or to the Uredo form, provided sufficiently good 

 data exist in older writings or herbaria to enable us to ascertain with 

 certainty whether the Uredo named actually was associated with the 

 teleutosporic form ; and this can in many cases be settled by reference 

 to older herbaria. The connection between teleutosporic and a3cidial 

 forms certainly was not suspected until recent years ; and, as it seldom 

 happens that in old herbaria the two forms are found intimately asso- 

 ciated, and, furthermore, as the whole group of ^cidia are rather 

 va^i^uely characterized by older writers and poorly preserved in her- 

 baria, it seems best to abandon the attempt to go back to the original 

 secidial name. Where the practice might succeed in one case, it would 

 produce uncertainty in many more ; and while, on the one hand, there 

 is danger that sufficient attention may not be paid to priority, there is, 

 on the other, still greater danger that, by attempting to do too much, 

 the nomenclature of Uredinece may become hopelessly entangled. 



In the North American Fungi a considerable number of forms of 

 ^cidium have been issued, sometimes with a reference on the label 

 to the teleutosporic form to which they have been referred, but in most 

 cases without such reference. In this country it seems to me that 

 in general a conservative policy had best be adopted in regard to asso- 

 ciating our ^cldla with teleutosporic forms. Information is always 

 to be desired ; hasty assumption, however, is an entirely different 

 matter. In Europe so many excellent observers have experimented 

 on the connection between different forms, that in regard to European 



UredinecB one can venture to make a statement of the subject in 

 systematic works. In this country almost nothing has been done in 

 an experimental way, and, if one will only bear in mind the peculiar 

 relations which ^cidia and Uromyces on Euphorhice are considered to 

 bear to one another in Europe, he will recognize that w^e in this 

 country cannot assume that, because an ^cidiinn and a Puccinia or a 



Uromyces occur on the same host, even when in close proximity, they 

 are really stages of one species. All one can say is that such is 

 probably the case. In papers describing our Uredinece one should of 

 course state, as far as he knows, what ^cidia are found with teleuto- 

 sporic forms ; but to go farther than this in our endemic species, anrJ 



