ZOOLOGY AND BOTANY, MICROSCOPY; ETC. 
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when applied to a surface of paraffin, it dries in two or three seconds. 
This has no tendency to cause the sections to roll. ... As soon as 
the collodion is dry, which ought to be in two or three seconds, cut the 
section, withdraw the knife, and pass the collodionized brush over the 
newly exposed surface of paraffin.’ The sections are placed collodion side 
down on the slide. They may be fastened by first painting the slide 
with a few drops of clove-oil collodion, placing them in it, and then 
evaporating off the clove oil. 
The sections are then placed in xylol for 15 minutes. This removes 
the paraffin. They are then washed in alcohol, afterwards with water, 
and stained. I have found no stain that was as effective in staining 
seeds as haematoxylin. They should be stained from 3 to 5 minutes. 
After washing the staining agent away with water, dehydrate with 
alcohol, and clear. Three parts of turpentine and two parts of carbolic 
acid make a very good clearing mixture. Canada balsam dissolved in 
xylol is used for mounting. In sections thus prepared one can dis- 
tinguish without difficulty in shepherd’s purse, golden-rod, or any endo- 
spermous seed, the coats, the plumule composed, as is the lower tip of 
the radicle, of small thin-walled nucleus-bearing cells. These two 
regions of growth are connected by slightly elongated cells, which are 
also thin-walled. The larger cells making up the tissue of the coty- 
ledons are stored with food. In many seeds a trace of a fibrovascular 
system may be seen ; also the peculiar arrangement and markings of the 
cells composing the coats. 
Seeds differ so much, that one would need to make many variations 
in method to suit different cases ; but as a general method I have found 
this to be a success, and I believe the histology of any seed may be 
demonstrated by applying it.” 
Microtome.* — Messrs. Bausch and Lomb write: — “We have found 
that the section-cutters formerly made by us and other manufacturers 
Fig. 14. 
