84 MANIPULATION 
Nore oN MANIPULATION. 
Dried specimens of Uredinales keep most of their characters 
unchanged for an unlimited time, but the colours fade except 
those of the teleutospores. The only two difficulties found in 
examining them are in regard to the markings on the outer 
surface of the spores, and the number of germ-pores. For the 
first, different methods succeed in different cases, but the finer 
markings can usually be seen by examining the spores under a 
one-sixth inch in air, or in water after squeezing out their 
granular contents by tapping or pressing hard upon the cover- 
glass. For the second, boiling for about a minute in a drop of 
lactic acid, on a glass slide over a spirit-lamp, is the best course, 
although expulsion of the contents under pressure frequently 
brings the germ-pores into view; in fact so plain do they often 
become that they can be photo-micrographed with ease. Boiling 
in lactic acid also restores old collapsed spores to their former 
size and plumpness. j 
The preparation from which Fig. 37 was drawn was 
obtained in the following way: lay the side of the leaf opposite 
to the sori in a thin layer of 5°/, KOH solution for an hour or 
so, then reverse and brush or scrape away the softened tissue 
as far as possible ; on mounting the remaining surface, epidermis 
upwards, in glycerine and water, the arrangement of the parts 
can be clearly seen. 
If it is wished to observe the germination of the spores in a 
hanging drop, almost any uredo will serve; for teleutospores 
Puccinia Malvacearum and for ecidiospores Zeidium Ficariae 
are usually the most handy. One of the best double stains 
to use is Diamant Fuchsin and Light Green; the former stains 
the nuclei red and the latter the cell-walls green. Stain heavily 
with the former and wash out with alcohol till the desired tint 
is arrived at; then use the Light Green dissolved in clove oil. 
