LX1II. Study of bone marrow. 



/. Appliances. Strong vice; five-eighths inch cover glasses; 

 microscope; heater; Ehrlich's triple stain (See Lesson 

 LXI) ; section of bone containing red marrow ; saw. 



2. Preparation. Clean cover glasses as usual and have 

 water in heater or fixing-plate boiling. 



j. Operation. Saw a transverse section of bone one inch 

 thick. Place it in the vice and turn the handle until the 

 bone marrow begins to ooze out on the surface. Just 

 touch the surface of this with one of the cover glasses 

 and proceed exactly as in exercise LXI a, making as 

 good a blood spread as possible. Dry smeared side up. 

 Then fix and stain as described in LXI b. Place slide 

 under the microscope and make a differential count of 

 red and white cells as in LXII. 



4.. Precaution. Have the bone specimen as fresh as possi- 

 ble. Saw the piece to be used just before putting it in 

 the vice and then take the specimen from the freshest 

 side of the bone. 



j". Observations. 



(1) What cells do you find that are not found in normal 

 blood ? 



(2) Can you trace these cells to the cells of normal 

 blood ? 



