XXXVIII.] FRESH TISSUES. 397 



with solid silver nitrate. Cut out the cornea and expose it to light 

 in water (p. 77). 



3. Tendons. These are hest made from the tarsal tendons, 

 which can readily be snipped off in considerable lengths. 



(a.) Fibrils. Tease a piece in baryta-water and mount in 

 glycerine. 



(b.) Tendon Cells. (i.) Add dilute acetic acid to bring into 

 view the rows of cells, then wash with water, and after 

 all the acid is removed stain with logwood or picro- 

 carmine. (ii.) Also tease a piece in normal saline con- 

 taining a trace of methyl-violet. 



(c.) Silver one of the tendons to show the endothelium cover- 

 ing its surface (p. [66). 



(7.) Place a fresh tendon in ammoniacal carmine (10-15 nains.), 

 wash and place in very dilute Delafield's logwood 

 (10-15 niins.). Wash, tease; and mount in balsam. 

 The tendon cells are red, their nuclei blue, and the 

 tendon fibres rosy. 



4. Aponeurosis. The best is the femoral. 



(a.) Kernove the membrane and stretch it on a slide by the 

 "semi-desiccation" method (p. 159), and after it is 

 fixed to the slide apply a drop of acid methyl-green, 

 or normal saline with methyl-violet. The nuclei are 

 thereby stained, and the crests and ridges of the cells 

 are made visible. 



(?>.) It may be fixed rapidly on a slide with absolute alcohol and 

 stained with logwood. Or osmic acid may be used to fix it. 



(c.) Show the effect of acetic acid. 



5. Areolar Tissue. (a.) Dissect out some from the inter- 

 muscular septa of the leg muscles. Stain with methyl-violet in 

 normal saline. This stains the cells. Or use acetic-fuchsin (p. 92). 



6. Yellow Elastic Fibres. These are found in the septa between 

 the lymph-sacs. Cut out a septum, fix it on a slide by "semi- 

 desiccation," and then add acetic acid. Or make another prepara- 

 tion and stain it with a weak solution of methyl-violet- 56 (p. 93). 



7. Pigment-Cells. (a.) These are found in the web of the frog's 

 foot. Stretch the web between the toes, harden it in absolute 

 alcohol for an hour or so, peel off the skin, and mount it in balsam 



(P- I73)- 



(b.) Or use the mesentery, or almost any blood-vessel ; add 

 dilute acetic acid and mount in glycerine. 



8. Hyaline Cartilage. (a.) Use either the episternum, scraping 

 off the perichondrium, or make a section of the articular cartilage 

 on the femur or tibia. Stain in hamiatoxylin. Or, before cutting, 

 the cartilage may be hardened for an hour in absolute alcohol 



