Gelehrte Gesellschaften. 
457 
Abbott, C. A., An improvement in tlie raethoil of preparing blooil serum for 
use in bacteriology. (Med. News. 1887. No. 8. p. 207 — 208.) 
llankin, E. II., Some new methods of using the auiline dyes for staining bac- 
teria. (Quarterly Journ. of Microscop. Science 1887. January. p. 401—411.) 
Unna, 1*. G., Die Rosaniliuo und Pararosaniline. Eine bakteriologische Farben- 
studie. (Studien, dermatologische, herausgeg. v. P. G. Unna. 4. Hft.) gr. 8°. 
73 p. Hamburg (Leopold Voss) 1887. 2 M. 
Berichte gelehrter Gesellschaften. 
American Academy of arts and Sciences. 
Sitzung vom 8. Dezember 1886. 
Herr Roland Thaxter sprach: 
On certain cultures of Gymnosporangiuin, witli notes on tlieir 
Roesteliae. 
(Schluss.) 
Turning next to R. lacerata, there seems to have been a con- 
fusion of forms in this instance also. The material thus uamed occur- 
ring in America includes at least two, and perhaps three forms; one, 
which for conveuience we will call lacerata, x, is found abundantly 
in this vicinity and further to the eastward on the fruit, stems, and less 
frequently on the leaves, of Amelanchier and Crataegus, during 
June aud July, wholly disappearing by the end of the latter month. 
A seeond form, lacerata, y, infests the leaves of Crataegus, and 
does not appear until early in August; while a third and smaller form, 
lacerata, z, is found abundantly on Pyrus Malus simultaneously 
with it. 
The first of these (lacerata, x) is very similar to Oersted ’s 
tigure of lacerata, and is identical with the European carpophila 
of Bagni s, distributed in Herb. Critt. Ital. II. 732, and in Myc. Univ. 
1326, while it occurs under lacerata in various other exsiccati on 
Crataegus, and seems undoubtedly distinct from the forms y and z, " 
of which the first is usually considered the more typical form of la- 
cerata, while the seeond is referred with some doubt to the same 
spccies. In general appearance it bears a superfioial resemblance to 
penicillata and pyrata; but although the peridium tends to be- 
come finely shredded, the shreds are straight, diverging- only slightly, 
without any tendency to curl outwards as in these species; nor is 
this tendency observable in single cells. The spores are large, having 
a diameter of about 27 p , while the peridial cells are long and narrow, 
about 90 X 16 p, the outline broken by fine, not very distinct rid- 
ges, the striae somewhat obscure and horizontal. 
In the forms y and z, the spores are smaller, about 20 p in di- 
ameter, while the peridial cells are smaller and broader in proportion 
to their length, about 20 X 65 p, with a tendency to a rhomboidal 
30 
