166 
METHODS IN PLANT HISTOLOGY 
slides may be covered with the plasmodium in a few hours. Perma¬ 
nent preparations may be made by immersing the slide in chromo- 
acetic acid, then washing and staining without removing the 
plasmodium from the slide. Acid fuchsin is a good stain for 
bringing out the delicate strands of the plasmodium. Iron-alum 
haematoxylin, followed by acid fuchsin or erythrosin, brings out 
both nuclei and cytoplasmic strands. 
Some of the foregoing methods are taken from an article by 
Professor Howard Ayers in the January and February (1898) 
numbers of the Journal of Applied Microscopy. Other methods, 
with directions for various experiments, are given in the same 
article. 
SCHIZOPHYTES (Fission Plants ) 
BACTERIA ( Schizomycetes , Fission Fungi) 
The methods of modern bacteriological technic are so numerous 
and so specialized that we must refer to laboratory manuals for 
instruction in this subject. The method given here will merely 
enable the student to study the form and size of those bacteria 
which are more easily demonstrated. 
Foul water at the outlets of sewers and such places will usually 
afford an abundance of Coccus, Bacillus, Spirillum , and Beggiatoa 
forms. Place a drop of water on a slide, heat it gently until the water 
evaporates, then stain with fuchsin or methyl violet, dehydrate, 
clear in xylol, and mount in balsam. 
The hay infusion is a time-honored method for securing bacteria 
for study. Pour hot water on a handful of hay, and filter the fluid 
through blotting paper. Place the fluid in a glass dish, and cover 
with a piece of glass to keep out the dust. When the fluid begins 
to appear turbid, bacteria will be abundant. The active movements 
are easily observed in a mount from the turbid water. As the 
bacteria pass into the resting condition, they form a scum on the 
surface of the water. Usually, the first to appear is a somewhat 
rod-shaped form, the Bacterium termo of the older texts. Spirillum 
and Coccus forms often appear later. 
Fine preparations may be obtained by inoculating a mouse with 
Anthrax, and then cutting paraffin sections of favorable organs. 
For making mounts of a dangerous form like Anthrax, secure properly 
fixed material from a bacteriologist. Stain in gentian-violet or 
