Dramatic demos

Janice M. Glime jmglime at MTU.EDU
Fri Mar 1 15:47:31 EST 1996


Here are a few more dramatic demos:

In the summer, or in the greenhouse, use Impatiens fruits and press on the
tow ends, squeezing the pod toward the middle.  The pod explodes and
shoots the seeds out.

Lycopodium lucidulum will shoot its gemmae out up to 3 feet if you press
down on them when they are mature.

Many mosses will flex their teeth as moisture changes.  Dicranella
heteromalla works particularly well.  Barbula and Tortula species work
well, but their teeth are fragile and will usually break when the plant is
stored.

Fern sporangia will fling their spores as their sporangia dry.  This can
be demonstrated by wetting some, then put over a warm lamp to dry. 
Sometimes you can persuade them to work with alcohol instead of water
because it dries better, particularly if they are moist to start.

Another dramatic one is to put Sphagnum in CaCl2 at about .5N and watch
the pH drop immediately.

Extract some red pigments from geraniums, then add a base to turn it blue
or add an acid to make it red.  The pigments are water-soluble, so you
need only grind them in a mortar and pestle with a bit of sand and water.

These are all fun and work well.

Janice
***********************************
 Janice M. Glime, Professor  
 Department of Biological Sciences
 Michigan Technological University
 Houghton, MI 49931-1295
 jmglime at mtu.edu
 906-487-2546
 FAX 906-487-3167 
***********************************






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