4 
PHARMACEUTICAL BOTANY 
III. Pteridophyta 
IV. Spermatophyta 
1. Lycopodineae 
2. Equisetineae 
3. Filicineae 
1. Gymnospermae 
2. Angiospermae 
f Lycopodiales 
Selaginalles 
1 Isoetales 
{ Equisetales 
j Ophioglossales 
1 Filicales 
Cycadales 
Ginkgoales 
Coniferales 
Gnetales 
J Monocotyledoneae 
1 Dicotyledoneae 
THE MICROSCOPE 
A microscope is an optical instrument, consisting of a lens, or 
combination of lenses, for making an enlarged image of an object 
which is too minute to be viewed by the naked eye. 
Microscopes are of two kinds, viz.: simple and compound. 
THE SIMPLE MICROSCOPE 
This consists simply of a convex lens or several combined into a 
system and mounted in a suitable stand. A good example of a 
simple microscope is a reading glass. 
THE COMPOUND MICROSCOPE 
A. Its Construction: 
The principal parts of a compound microscope are: 
r. The base, generally horseshoe shaped, which rests on the table. 
2. The pillar, an upright bar, which is attached to the base below 
and supports the rest of the instrument. 
3. The stage, a horizontal shelf upon which is placed the prepara- 
tion or slide to be examined. The stage is perforated in the center 
for transmitting light reflected up by the mirror. On the stage are 
two clips for holding the glass slide. 
4. The mirror, situated below the stage, by which the light is 
reflected upward through the opening in the stage. 
