Notes . 
179 
The flowers to be preserved are put into water saturated with 
sulphurous acid, to which methylated alcohol (ordinary strength) is 
added in the proportion of one part of alcohol to three parts of 
water. Plants with thick leaves are left in the fluid for a day or a 
day and a half, delicate flowers only from five minutes to half an 
hour. The specimens are then removed and the fluid on the surface 
is allowed to evaporate by exposure to the sun or artificial heat, and 
when this has taken place the specimens are then placed between 
sheets of drying paper in the usual way. As a rule it is not necessary 
to change the paper. Treated in this way plants either retain from 
the first their natural colour, or, as sometimes happens, the colour, 
which alters slightly at first or even disappears altogether, is regained 
in a short time. Flowers especially scarcely lose any of their natural 
splendour. A difficult part of the process in the case of delicate flowers 
is the laying out of the parts upon the drying paper after treatment 
in the solution. 
Not only does the method preserve colour but it also hastens the 
process of drying. As instances of this Mr. Hennings mentions that 
the globose stems of Euphorbia globosa were dried in three days, the 
juicy and thick rosettes of species of Echeveria \ Crassu/a, and Semper - 
vivum in two days, the fleshy inflorescences of Orchideae, Araceae, 
Melastomaceae in one day, and all kept their natural colour completely, 
or nearly so. Plants too which usually turn black on drying, such as 
Lathraea squamaria, Melampyrum , and others, when treated in this way 
keep their natural colour. 
A solution once made may be used over and over again. 
SELMAR SCHONLAND, Oxford. 
THE APICAL MERISTEM IN THE ROOTS OP PONTE- 
DERIACEAE. — The structure of the roots of the Pontederiaceae 
has already been repeatedly investigated. Nageli 1 , who first gave an 
account of them, chiefly directed his attention to the mode in which 
the rootlets of the adventitious roots in Pontederia (now Eichhornia ) 
crassipes , Mart., arose. As far as the first stages of their development 
are concerned I have nothing to add to his observations. As to more 
advanced stages I cannot agree with him, but I shall refer to this again 
later on. 
1 Nageli u. Leitgeb, Beitrage zur wissenschaftl. Botanik, Hft. 4 (1868), p. 138. 
