The hairs onyourhead havetheirroots in the lower layer of the scalp.
Therootis actuallya collectionofcells in the scalp from which the hair grows.
Thecolorofyour hair is due to pigment,coloringmatterin the cellsof
your scalp. Hairbecomes grey whenpigmentfails to form at all.
THE STRUCTURE OF COTTON FIBRES
Materials:A small pieceofabsorbentcotton(justenough to fit between
yourthumband forefinger), a glass slide, a cover slip, a medicinedropper,
a glassofordinarytap water.
Follow this procedure:Tease a fewstrandsofabsorbentcottonapartand
place them on adropof water in the middle of a glass slide. Protectthis with
a cover slip. Putthe preparedslide in the middle of the microscope stage.
Observe it firstunderlow power, and thenunderhigh power.
Youwillobserve:Thecottonfibresappeartransformed into large strings
or tubesunderlow power. Of course, they are even larger under high power.
Absorbentcottonis composedofmanyindividualthreadsthatarematted
together. Butunderthe microscope each fibre shows up as aseparatethread,
sothatyou can see the truecompositionofthecotton.THE INTRICATE STRUCTURE OF FISH SCALES
Materials: Getsome small fish scales from your grocer or fish dealer.
To keep them from drying out, wrap them in moist kitchen papertowelling.
You will also need a medicinedropperand a glass of water.