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METHODS IN PLANT HISTOLOGY 
The cilia of the motile spores of Thallophytes may often be 
demonstrated by allowing a drop of the iodine solution used in testing 
for starch to run under the cover. 
Zimmermann gives the following method: Bring the objects into 
a drop of water on the slide and invert the drop over the fumes of 
1 per cent osmic acid for 5 minutes. Allow the drop to dry. Then add 
a drop of 20 per cent aqueous solution of tannin, and after 5 minutes 
wash it off with water. Stain in a strong aqueous solution of fuchsin 
(or carbol fuchsin) for 5 minutes. Allow the preparation to dry 
completely, and then add a drop of balsam and a cover. The cilia 
should take a bright red. 
Zimmermann also found the following method satisfactory for 
the cilia of the zoospores of algae and fungi: Fix by adding a few 
drops of 1 per cent osmic acid to the water containing the zoospores; 
then add an equal amount of a mixture of fuchsin and methyl violet. 
The fuchsin and methyl violet should be 1 per cent solutions in 95 per 
cent alcohol. In a few seconds the cilia stain a bright red. 
CHONDRIOSOMES 
During the past fifteen years the terms chondriosomes, mito¬ 
chondria, Chondriokonten, Chondromiten , etc., have become increas- 
Fig. 28.—Cells from the periblem of the root-tip of Allium cepa: A, chondriosomes; B, 
canaliculi: fixed in Bensley’s solution and stained in iron-alum haematoxylin. X 1,200. 
ingly frequent in botanical literature. These “ chondriosomes,” 
as we shall call them, are minute structures, probably present in most 
cells, but not differentiated by the most usual methods and generally 
overlooked when they might be seen. Most of them are as small as 
bacteria and bear a superficial resemblance to coccus, spirillum, 
and bacillus forms (Fig. 28A). 
