1892.] THE MICROSCOPE. 209 



8i. Are the so-called Jiesh-ivorjjis in the ski?i really wor??is? 

 — Medic. 



No. They are simply plugs of the normal sebaceous matter, 

 the external end blackened with dirt. When pressed out they 

 closely resemble a small black-head worm, but a careful exami- 

 nation will reveal their true character. 



82. Is the itch a disease or a multiplicity of parasites ? Is 

 the barber^ s itch the same? — Scratc/ier. 



Itch, or scabies, is caused by a minute eight-legged insect 

 which burrows under the outer skin and lays its eggs as it goes 

 along. The irritation of this proceeding causes the itching. The 

 eggs or young of this parasite are spread about by violent scratch- 

 ing and they may be easily transferred to another person by con- 

 tact. 



Barber's itch is a fungus atiecting the hair just below the sur- 

 face of the skin. 



S3. Are the coinpanion colors ever foiutd in the sa?ne species 

 of plant ? Why does the green wheat turn yellow and the 

 green forest leaf turn red. — H. E. E. 



It has been said that no one species of plant exhibits all the 

 primary colors in its flowers. This is probably the rule, but there 

 are exceptions. The Flowering Pea, Stock, and Linum show 

 all the primary colors. The Dahlia, Portulacca, Chrysanthemum, 

 and others show two primaries and a secondary, the latter color 

 usually a purple. Cultivation may be largely responsible for this 

 variety. 



84. I have read that gold may be reduced to so thi?z afihn 

 that light seefi through it appears green. Does this color ap- 

 pear when it is seen with the microscope? — Optician. 



Verv thin films of g:old transmit a g-reenish lis^ht, but are vellow 

 by reflected light. If the film be heated on a glass plate trans- 

 mitted light will appear ruby red ; if burnished down the green 

 tint reappears. These facts are accepted as a proof that gold is 

 semi-transparent. There is no record of a microscopical exami- 

 nation of these extremely thin films. 



85. What., if any 1 is the diff'erence betzveen a sunfish {au- 

 relia^ and a jellyfish? See The Microscope., vol. xi^ pge. 222. 



An aurelia is a medusa, or jelly-like radiate animal. It is not 

 a fish, and should not be called a sunfish. The true marine sun- 

 fish is a tropical species, weighing several hundred pounds, and 

 is a true fish, frequently found basking in the sun, showing a por- 

 tion of its body above the surface of the water. 



