A HUNDRED MICROSCOPICAL OBJECTS 2:39 



76. Cleavage of the Ova of Hookworm. — The c^j^s of 

 hookworms can be separated by washing and decantation 

 from the faeces of infested cattle. They are transparent 

 and show cleavage well. Water-immersion objective. 



77. Embryo Chick. Alive. — Cut from the egg at inter- 

 vals during the first 50 hours of incubation. Use cover- 

 glass and dry objective, such as 10 or 20 apochromatic, 

 on the preparation in normal salt solution on a warm 

 stage. 



78. Human Blood (or Frog's or Salamander's Blood, 

 Drawn from the Heart with a Pipette). Fresh. — Cover 

 sealed with melted paraffin. Apochromatic water-immer- 

 sion objective 70. 



79. Same Object. — Viewed with cardioid or bicentric 

 condenser, and special oil-immersion objective 60, of 1.0 

 aperture. 



80. Same Object. — Smear. Dried. Fixed by heat. 

 Stained with eosin and methylene blue. Viewed by oil- 

 immersion objective without cover-glass, the tube length 

 being increased a few millimeters (about 15 millimeters for 

 a 90 objective). 



81. Same Object. — Smear. Fixed by heat. Stained by 

 Giemsa's method. Viewed dry in dark field of achromatic 

 immersion condenser, by 20 apochromatic objective, the 

 tube length being increased 35 millimeters as in 50 (or a 

 0.17 mm. cover being put on). (Coles.) 



82. Same Object. — Thick smear. Nearly dry, and fix 

 with chrom-acetic-formalin. Stain with iodine gentian- vio- 

 let, or alcoholic iron-hsematoxylin, or with iron-brazilin. 



83. Same Object. — Thick smear treated with iron- 

 acetocarmine. Cover 0.17 millimeter thick. Shows nuclei. 

 High-power water-immersion objective. 



84. Same Object. — Nigrosin smear, as in 52. 



85. Blood with Malarial Parasites. — Viewed after treat- 

 ment as in 80. 



86. Blood with Trypanosomes. — As in 81 and 84. 



87. Blood with FUaria.— As in 78 and 82. 



