Follow this procedure:Puttwo drops ofwaterin the middle ofa clean
glass slide. Put a fish scale in thewaterandholdin place with a cover glass.
Observe firstunderlow power, and thenunderhigh power.
You will observe:The dried fish scalethatlooks so tiny andunglamorous
in yourhandshows upunderthe microscope as abeautifulsculpturedstructure.
Concentricridges willappear,makingthis single scale resemble acomplicated
abstractdrawing by amodernartist.
Scales grow on a fish's body in the same manner as the overlapping
shingles are placed on theroofofa house. Theattachmentofthe scale is
towardthe headofthe fish. The wider,overlappingpartof the scale faces the
tail of the fish. Thisoverlappingarrangementof scales provides the fish with
a coatofarmor,asprotection,and also with ahard,sleek covering forcutting
throughthe water as it swims.
Each species(closely related group) offishproduces scalesthathave a
characteristicpattern. Ifyouwantedto observe hundredsoffish scales and
cataloguethem, you could eventually tell the speciesofa fishjustby examining
a single scaleunderyour microscope. Thepatternof lines on the scale would
reveal the fish's family to an experienced eye.
TYPICAL CELL STRUCTURE- "EMPTY" CORK CELLS
Materials:A thin piece of the roundedsideofa bottlecork, asharp,
single-edgedrazoror aparingknife (withMotherorDad'spermission), a glass
oftapwater and a medicinedropper.
Follow this procedure:SliceotTa very thin piece of the cork. Putthis in
twodropsofwater on the slide and cover with the cover slip. Try to slide one
edgeofthe cover slip slowly on the slide, so it can settle; this will helpprevent
bubbles forming on your slide. Place thepreparedslide on themicroscope