Evening star., 1933-08-27

hydra. showing . whole population OF para
on . dog. Here Is . spinning colony OF the
primitive plants called volvox . swarm OF
dancing vinegar worms the grOtesque larvae OF
damsel flies and day flies
But the part Of DR.. Roemmert's show" that
gets the most fascinated attention from the
crowds Is q veritable Roman holiday of the
microscopic world, . display Of herceness and
flesh hunger on the part Of invisibly small
one-celled creatures that is as awesome as
though they were tigers or ieopards.
First DR.. Roemmert shows you his little
beasts Of prey-sman. apparently completely
round objects that swim about actively but
do not look 1t all formidable Indeed, they
look more like . lot of rolling marbles than
anything else. But each Of them has q tiny,
nose-like beak. which it can use most effec-
lively when occasion demands.
THEN be displays q screenful Of the animals
shcw; they are the common, harmless one
celled creatures called slipper animalcule or.
more learnedly Paramecium. They are larger
than their prospective devourers. but Is de-
fenseless against them Is cattle are against
leopards.
Dr. Roemmert now pushes the edges OF the
two slides together permitting the liquid drops
under each to mix. The round animalcules
mingle with the slipper shaped ones
There Is q seconds swimming about, As they
orient themselves, and then. with ferocity
that makes you shudder, each predatory beastlet
selects its victim. seizes it with an unshakable
grip and proceeds to devour It alive
Sometimes two will seize the same victim
at opposite ends and eat away until they meet
in the middle. Then they let 60 and pursue
their separate ways. The predators never fight
each ether, and strange to say never attack
anything but just one species OF victim.
DR.. Roemmert explains, with considerable
emphasis that he Is not running . commercial
exhibit Of any kind. He Is not selling the
projectors he uses. nor any Of the parts used
in making them. He Is interested only In pro-
noting the idea Of using this type of projection
In educational work and for the Interest Of
the general public.
He believes, as do all educators who have
seen his exhibit, that this method can be used
with great advantage in school and college
class rooms, and for popular lectures and demon-
strators as well. Various types Of projectors
can be had at reasonable prices, or you have
q microscope and an old-fashioned stereopticon
lantern you can even build one yourself. But to
deal with the animals you win need patience
and experience
Other fascinating biological exhibits In the
Hall Of Science win their crowds not because
they are alive but because they are 50 ingeni-
ously constructed that they seem to be alive.
Prominent among these Is one showing just
three cells of green plant, painted out 90 huge
that the tiny green color discs OF chloroplasts
in them show up as big as soup plates. These
cells demonstrate the processes that 60 on In
all green plants, in the manufacture Of food and
in its use by the plant itself.
TRAINS Of light fecks, projected against the
! transparency from behind. show the courses
followed by water, oxygen and carbon dioxide
in the vital economy Of the plant. One set
of these moving light hecks shows how carbon
dioxide enters the cell and passes into the
chloroplast
Into the same chloroplast water Is also being