SECTION IX. HISTOLOGY 



The slides loaned you have been prepared by preserving the 

 tissues, cutting them in thin slices (sections) (except the 

 blood, which has been smeared on the slide) dyeing them 

 in contrasting colors, and mounting them in a transparent 

 resin under the coverslip. By careful study you can iden- 

 tify on them examples of the principal tissues of the 

 vertebrate body. 



1. Blood 



In the slide given you observe 



298. the erythrocytes (red blood corpuscles). These are 

 elliptical cells with deeply staining oval nuclei. 



299. The leucocytes (white blood corpuscles). Much 

 fewer in number, these may be recognized by their 

 irregular shape, large granular and often irregularly 

 shaped nucleus and the occasional presence of gran- 

 ules in the cytoplasm. 



300. The blood-plasma is represented by the faintly 

 staining background between the cells. Some slides 

 may show a few twisted elongated cells with small 

 nuclei and flagella. These are parasitic protozoa, 

 Trypanosoma ranarum. 



Drawing 24. Draw examples of erythrocytes and 

 leucocytes highly magniHed. 



2. Cartilage (Hyaline) 



In the slide provided you, identify 



301. the cartilage cells, small, ovoid and often associated 

 in groups of two, four, etc. Study under high power. 



47 



