132 
SUMMARY OF CURRENT RESEARCHES RELATING TO 
be killed in glacial acetic acid, and left in it for 5 to 10 minutes. It 
should be removed tbence directly into aqueous alum cochineal or alum 
carmine solution for a half to one minute, then washed and mounted in 
water, the cover slip being ringed with Canada balsam or gold size. As 
may be supposed, however, these specimens are not very permanent, and 
become clouded on long standing. 
Preparation of Flower-Buds.* — M. M. Raciborski recommends the 
following process for preparing flower-buds from herbirium specimens 
for microscopical examination. The specimen is steeped for some hours 
in alcohol ; then for two or three hours in water, and finally for 24 hours 
in 50 per cent, ammonia at a temperature of about 40° C. After the 
ammonia has been removed by water, and then by alcohol and toluol, the 
object is imbedded in paraffin and fixed to the slide by white of egg. In 
flower-buds taken from specimens that had lain long in the herbarium, 
the position of the tapete-cells in the embryo-sac could frequently be 
made out, and even the nuclei of the pollen-grains could be detected. 
(3) Cutting-, including- Imbedding- and Microtomes. 
Automatic Microtome. f — The late Prof. J. A. Ryder devised the 
new microtome shown in fig. 26 in order to facilitate the preparation of 
Fig. 26. 
sections for large classes, and also for the rapid preparation of series of 
sections in embryological work. It differs from the majority of auto- 
* Flora, Ixxxi. (1895) Erganz.-Bd., pp. 152-3. 
f Ainer. Mior. Journ., xvi. (1895) pp. 216-20. 
