1 6 Ward. — Recent Researches on the Parasitism of Fungi . 
There is one observer who has done excellent service in this connexion, 
to whom full justice has hardly been done, and the matter appeals to us 
especially here because he is almost a local man — I refer to Dr. C. B. 
Plowright of King’s Lynn. 
Between 1880 and 1900 Dr. Plowright published a large series of papers 
on the Uredineae, as well as a monograph (129) on the British Uredineae 
and Ustilagineae, and it is to be noted that this long-sustained and important 
work (so far as the Uredineae are concerned) was done in the intervals of 
a busy practice as a medical man. 
Not the least of Dr. Plowright’s contributions must be reckoned his 
clear-sighted recognition of a series of forms which are only distinguishable 
by their biological, and not by their morphological peculiarities. Among 
others I may mention the Gymnosporangia , Puccinia Pkragmiiis i P. Phala - 
ridis, and the various forms of Puccinia on Carex (129-35). 
Eriksson’s Formae Speciales . 
It is to Eriksson, however, that we owe the clearest exposition of 
the idea of specialized parasitism, since his paper in 1894 (60) on the 
breaking up of the old species P. grammis into at least two species and 
a number of special forms ; as well as his work on the unravelling of the 
chaos of special forms in the species P. glumarum , P. disperse P. coronata , 
and P. coronifera. 
The application of Eriksson’s results at once led to the establishment 
of specialized forms for the species of Puccinia on Phalaris , Carex , &c., 
and those of Melampsora on Willows. 
In his paper in 1901 (61, p. 101) Eriksson summarizes the results of 
infection experiments which led him to break up the older Puccinia 
graminiSyP. Rufrigo-vera, &c., into finer ‘ species ’ and races. These results 
may be put shortly as follows : — 
Species I. P. graminis, Pers., the Black Rust of cereals, is heteroecious on 
Barberry, and has at least six specialized forms : 
F. sp. 1. Secalis, on Rye, Barley, Triticum repens , and some other Grasses; 
but not on Wheat or Oats. 
F. sp. 2. Avenae, on Oats, Dactylis , Alopecurus , and some other Grasses; but 
not on Wheat. 
F. sp. 3, Tritici, on Wheat, but not on the other cereals or Grasses. 
F. sp. 4. Airae, on Air a caespitosa only. 
F. sp. 5. Agrostis, on Agrostis only. 
F. sp. 6. Poae , on Poa only. 
Species II. P. Phlei-pratensis (Er. and Henn) is the Black Rust of Phleum 
pratense and Festuca elatior , and was formerly regarded as identical with P . graminis ; 
its aecidium is as yet not known. It was hitherto included under P. graminis , but 
owing to its inability to infect Barberry or Wheat it must be separated. 
Species III. P. glumarum (Er. and Henn), the Yellow Rust of Wheat, was formerly 
