1899] BRIEFER ARTICLES " 423 
A microscopical examination made sometime afterward revealed 
some noteworthy peculiarities in the shape, size, and number of cells 
in the teleutospores. The usual two-celled spores were present but 
accompanied by others having one, three, and four cells, 
The different forms were about equal in number but differed con- 
siderably in size, the four-celled variety being the largest, as one would 
naturally expect. Of each form ten measurements were made, giving 
the following extremes: one-celled, 27-36 X15-20n; two-celled, 30— 
45X 15-21; three-celled, 45-54 15-21; four-celled, 52-66 15— 
20m. 
The one-celled spores might easily have passed for the teleuto- 
spores of some Uromyces such as U. graminicola Burrill. The two- 
celled ones were quite normal. in size and shape, except that in some 
the pedicels were much stouter than are usually found in P. graminis, 
more closely resembling the pedicels of P. emaculata Schw. The three 
and four-celled forms were of three kinds, some having the upper septum 
horizontal, some oblique, and others vertical, as though the upper cell 
had been formed as a sort of afterthought, by the division of the second 
or third cell as the case might be. 
In these the evolutionary development of several genera of Ure- 
dinae could be plainly traced, passing from the lower Uromyces 
through Puccinia and Triphragmium to Phragmidium. The spores, 
aside from the number of cells, were not likely to be mistaken for 
those of Triphragmium or ‘Phragmidium, as they were quite different 
in general appearance. ‘These genera have undoubtedly a common 
origin, and must be looked upon as being more highly developed, 
more specialized, in direct relation to the number of cells in the spores, 
as itis quite apparent that a larger number of sporidia can be pro- 
duced with less effort in those having the larger number of divisions 
in the spores.— H. HaroLp Hume, /owa State College, Ames. 
WHAT IS PRUNUS INSITITIA? 
In the June number of the BoranicaL GazeTTE there appeared 
‘n article under the heading given above and written by Frovessor 
P. A. Waugh. The conclusion to which the author qr: his own 
Words, is “that there is no such species as Prunus insiitia. 
: n 
To me this seems rather strange. I happen to have a 
the land of Linneus and received a large portion of my botan 
