390 NOTES AND COMMENTS [DECEMBER 
other features. Zriphragiuwm clavellosum, for example, is confined to 
Aralia nudicaulis, and differs from 7. Credelae, which lives on Credela 
chinensis, merely by the size of the spores, a difference which does not 
exceed the dimensions of a single micron. 
Such forms must obviously be looked upon as having sprung from 
a common ancestor, which in this case must have lived on both hosts 
indifferently, especially as the two species agree in the possession of 
characters which distinguish them sharply from all other Triphragia. 
Another example is supplied by Leptopuccinias like P. Arechavaletae 
living on Sapindaceae, P. heterospora on Malvaceae, P. Hlytrariae on 
Acanthaceae, and P. Lantoneae on Verbenaceae, all of which closely 
resemble each other in the form of their spores and spore-beds ; while 
all possess in common such distinctive characters as the preponderance 
of unicellular teleutospores, isolated individuals of which may reach a 
much greater size than their fellows, and the occasional occurrence of 
isolated bicellular spores which also vary in size, and the septum of 
which is often oblique, while the only morphological differences are to 
be found in slight diversities in the size of the spores and in the 
thickness of their walls. 
Further evidence of the same kind is furnished by the only three 
Puccinosiras known, and may probably be found in a number of other 
heteroecious forms. 
A striking morphological resemblance is also observable between 
certain Leptopuccinias and the teleutospores of heteroecious species 
parasitic on widely different plants, but possessing aecidia which live 
on the same hosts as the Leptopuccinias in question, e.g. Puccinia 
aecidit leucanthemi, which forms aecidia on Chrysanthemum 
leucanthemum, gives rise on Carex montana to teleutospores which 
closely resemble those borne by the Lepto-form Puccinia leucanthemi 
on the former host. 
Professor Dietel cites a large number of such correspondences, and 
believes that they point to the origin of the heteroecious and Lepto- 
forms in a common ancestor inhabiting such widely different hosts as 
Carices and Composites, while, on the other hand, Professor Magnus is 
of opinion that the resemblance is purely accidental, and ascribable to 
the great similarity existing among Leptopuccinias as a whole, owing 
to adaptation to their peculiar mode of life. 
The coronate Puccinias, including, along with those heteroecious 
species which form their aecidia on Rhamnus, the two Leptopuccinias 
also living on the same host, and P. Festuwcae, which forms its aecidia 
on Lonicera, are distinguished from all other Uredines by the possession 
on the teleutospores of a crown of processes which appear to be devoid 
of adaptational significance, and must be considered as pointing to a 
common ancestry for these forms, especially as the only other Uredine 
inhabiting Lonicera is Puccinia longirostris, in which the crown is 
replaced by a single long process on the apex of the teleutospore, but 
