164 BOTANICAL GAZETTE 3 [aucust 
that it is not certain that the species of Mespilus entering into the foregoing 
chimaera is immune, and even if it were, the result of the experiment does not 
imply that the Mespilus epidermis had become susceptible, since it is known 
that germ tubes of fungi frequently penetrate inert membranes and even the 
epidermis of plants in whose tissues they are unable to make any further growth. 
RTON® describes a number of cases of correlation in the distribution of 
certain heteroecious species of Puccinia and Uromyces. The forms thus cor- 
related have for their telial hosts the same species or closely related species of 
the same genus, while their aecidia occur on alternate hosts which are either 
identical or which are species of one genus. The aecidia and the uredospores 
of the associated rusts are similar in structure, form, and color, while the 
teleutospores differ only in number of cells. As examples may be cited 
Puccinia subnitens and Uromyces Peckeanus, both of which occur on Distichlis 
Spicaia and have aecidia similar in their essential characteristics on species 
of the Chenopodiaceae; also Puccinia Caricis-Asteris and U. romyces perigynius 
with teleutospores on species of Carex and aecidia on members of the Com- 
positae. This condition appears to point to a close relationship between the 
two genera Puccinia and Uromyces. 
In opposition to the view that rust-infected grains of cereals are the agencies 
by which the grain rusts are carried over from year to year, ERIKSSON” points 
out that grains bearing rust pustules are, both in his own experiments and 
according to statements in the literature, of very rare occurrence; and that 
plants developing from such grains do not become infected earlier nor more 
_ Severely than plants from normal seeds. F urthermore, a cytological study of 
a large number of plants from plots which afterward were badly rusted failed 
to show the presence of mycelium by means of which the rust might have 
lived through the winter, He concludes, therefore, that the rust pustules on 
infected seed grain are of no significance in connection with the rust of the 
grain crop.—H. Hasseprine. 
Chloroplasts and chlorophyll.—Lirsaipr’s work'™ on chloroplasts 
emphasizes again the important part colloidal chemistry is coming to play in 
physiological problems. The chloroplast is considered a two-phase disperse 
system. The pigments, especially the green ones, constitute the lipoid phase, 
and the stroma, insoluble in lipoid solvents, coagulable with heat and alcohol, 
and swelling in water, is the hydroid phase. The lipoid phase shows amicronic 
(in particles beyond the vision of the ultramicroscope) dispersal through the 

* Orton, C. R., Correlation between certain species of Puccinia and Uromyees. 
Mycologia 4°104-204. pls. 2. 1912. ; 
KSSON, J., Rostige Getreidekirner- und die Uberwinterung der Pilzspecies: 
Bakt. IT. 32°453-459. 1912. 
_ JEBALDT, Erna, Uber die Wirkung wisseriger Lésung oberflachenaktiver 
Subitanzen auf die Chlorophylikérner. Zeitsch. Bot. 5:°65-113. 1913. 
10 Err 
Centralbl. 
