NEW PUBLICATIONS. 61 
once the fifth form of fruit, the wredo. Lastly, the same mycelium 
which produces the uredo ultimately yields the feleufospores, which in 
some species of Uredinee are found on the same fruit-layer with the 
uredo-spores, in others in special fruit-layers. S 
idium and Uredo (as is well known) have been hitherto considered 
genera. De Bary observes that the names may be retained as descrip- 
tive of the organs, but that the genera must bear the names hitherto 
applied to the Zeleutospores. 
The author remarks that it is hardly to be doubted that the cycle of 
development, commencing with the germination of the teleutospores, 
exhibiting the stages of promycelium, sporidia, ZEcidia, with spermogonia, 
and «redo, and thus returning to the ¢eleutospores, is probably the same, 
or nearly so, in all the Uredinee. 
But many species of Puccinia and Uromyces seem never to produce 
an ZEcidium, and inhabit plants upon which Æcidia are never seen. 
The question thus arises whether the Zcidium stage is suppressed, or 
is it to be sought for elsewhere. 
Dr. de Bary selected Puccinia graminis, P., for special study, with 
the view of determining this question, and k has carried out a series 
of careful ccs (for the details of which we must refer to the . 
paper itself) which have satisfied him that the sporidia of Puccinia 
graminis germinate on the leaves of Berberis, and that the ZEcidium of 
the Berberis is a stage in the cycle of development of that Puccinia. 
Thus, whilst in most Uredinee the entire development is carried out 
upon one and the same nutrient plant, the alternations of generation in 
Puccinia graminis require a change of host. 
This (Dr. de Bary observes) is a peculiarity to be especially re- 
marked, and he proposes to call those parasites whose metamorphosis 
and alternations of generation require a change of host, heteracious, 
and those whose whole development is carried out upon the same host, 
autecious. This Aefereciousness (so to speak) is well known in the 
animal kingdom in the Tenie and Trematoda, but Puccinia graminis is 
the first of the parasitic fungi in which it has been certainly asce 
The author indicates several of the Uredinee (Melampsora, Piragni- 
dium, etc.) which, although yielding sporidia, uredo, and tel 
exhibit no Zcidia, but on the other hand several Æcidia of which a 
other stages are quite unknown. 
We may add that the paper contains a somewhat full account of the 
