IO 
V. II. Blackman — 
the latter case it is best if possible to prevent darkening by very rapid 
killing, e,g. in boiling water or boiling alcohol, or by bleaching in 
acid alcohol (90°/ o alcohol with 2°/ 0 by volume of HC1) in sunlight 
before transference to the alcohol in which they are to remain. 
If this has not been done, and the specimens are already darkened in 
alcohol, they can be bleached in acid alcohol in the same way, but 
this is not always effective. 
Photoxylin (which can be obtained from Grubler of Leipsig) is 
strongly recommended as a cement for attaching light objects 
preserved in strong spirit, while gelatine has to be used for heavy 
specimens. For coloured pointers to indicate parts in labelling 
specimens preserved in liquid media, an ingenious use is made of 
capillary tubes filled with coloured plaster. 
The paper is illustrated by two excellent photographs, one of a 
dry object—fruit of sycamore; the other wet—the fruit of Phallus 
impudicus, each showing a set of specimens fully dissected and 
labelled to illustrate structure. 
ON THE CONDITIONS OF 
TELEUTOSPORE GERMINATION AND OF SPORIDIA 
FORMATION IN THE UREDINE^E, 
By Vernon H. Blackman, M.A., 
Assistant, Department of Botany, British Museum. 
[With Figs. 4-6 on Plate I.] 
4 S is well known the germ-tube produced by the germination of 
the teleutospores of the Uredineae is usually described as of 
limited growth. Such a description, however, is not altogether satis¬ 
factory, for since all the Uredineae are, as far as is known, obligate 
parasites at all stages of development, the growth outside the tissue 
of the host of any germ-tube or hypha must necessarily be strictly 
limited by the amount of reserve material at its disposal. In the 
case of the teleutospores the term is, however, used in reference 
to the fact that under the usual conditions the germ-tube after 
developing to a certain extent ceases to grow, and gives origin 
to the four sporidia-bearing cells, becoming, in fact, so-called 
promycelium. 
