96 
W. B. Grove. 
it is continuing to be autoecious in this country, where Impatiens is 
very rare, although it is at the same time evolving here a Micro¬ 
puccinia which has not yet been found in America. We have, in 
fact, a case parallel to that diverse evolution of the biological races 
of P. graminis which is taking place at the present time in three 
distinct directions in Europe, North America and Australia 
respectively. 1 Whether the Balsaminaceae, to which Impatiens 
belongs, are to be considered as of a higher type than Adoxa is a 
matter about which there might be two opinions, if Adoxa is placed 
among the Caprifoliacese; personally I should have little hesitation 
in putting the Balsam, with its complicated floral and fruiting 
mechanism, far above the simple little Moschatel. 
Sub-divisions of Puccinia. 
Before we conclude that the theory suggested by these ex¬ 
amples (which might he largely increased) is fully justified, there 
are other aspects of the question to be considered. It is obvious that 
the great genus Puccinia, comprising now about 1,300 described 
species, must sooner or later be divided—whether into sections, 
sub-genera, or genera, matters not. Even in the 130 species of our 
British flora, some sub-division is necessary for the sake of clear¬ 
ness. Four attempts at such arrangements have been made. 
Schroter (22) instituted the sections Eupuccinia, Pucciniopsis, 
Brachypuccima, Hemipuccinia, Micropuccinia, and Leptopuccinia, 
based upon the number and nature of the spore forms known. 
Thus, designating spermogones by O, aecidia by I, uredospores by 
II, and teleutospores by III, his sections may be defined (in the 
light of our present knowledge) as follows :— 
Possessing 
O, I, II, III 
O, I, III 
O, II, III 
II, III 
[O] III 
( Auteupuccinia, all on the same species; 
Eupuccinia j Hetereupuccinia, O and I on one 
( species, II and III on another. 
Pucciniopsis. 
Brachypuccinia. 
( Possibly most (though not all) of 
these will be found in the future 
to be heteroecious. 2 
Micropuccinia Spermogones not always occurring. 
1 In Australia, according to McAlpine (17), P. graminis has completely lost 
the power of infecting the Barberry, which is not a native of that country. 
2 It would seem possible to determine whether a supposed Hemipuccinia 
belongs to a heteroecious species or not, by cytological investigation. If the 
first-forrped mycelium of the uredo-stage is binucleate, the fungus in question 
must be a stage of a heteroecious species : if not, if the binucleate condition 
arises in the course of development of the uredo, then it is a true Hemipuccinia. 
Of the fourteen species included under this head in Plowright’s Uredinex (21), 
five have been already proved to be heteroecious, and three others are strongly 
suspected to be so, 
