4(3 CONNECTIVE TISSUES. 



dilute solution of glycerine, may even be brushed with a camel- 

 hair pencil moistened with water (of course not too vigorously), 

 without preventing the occurrence of the silver lines. Again, 

 in a section prepared from a fresh mucous membrane, with 

 laminated pavement epithelium, which section has been colored 

 in silver, the silver lines corresponding to the borders of the 

 individual cells are distinguishable throughout all the layers. 

 Further, silver lines corresponding with the borders of the in- 

 dividual muscle cells are met with in unstriped muscular tissue 

 which has been colored in silver, as, e. #., in the muscular coats 

 of arteries. These facts justify the assumption that the silver 

 lines are caused by precipitations in the albuminous intersti- 

 tial substance which bounds and separates the individual 

 cells. 



CHAPTER III. 



CONNECTIVE TISSUES. 



UNDER this heading we include the fibrous tissues, with the 

 cellular elements which they contain, the elastic tissues, carti- 

 lage, and bone. 



Fibrous Tissue. Fibrous tissue consists of delicate gela- 

 Vigenous fibres, which are connected by an interstitial albumi- 

 nous substance. The fibres form bundles of various thickness, 

 which either have a parallel arrangement, as in tendons and 

 fasciae ; or form a meshwork by the> spliting and reunion of 

 neighboring bundles, as in the omentum, the submucous and 

 subcutaneous tissue ; or, finally, l^ave a felt-like arrangement 

 in which the bundles cross each other, or twist round one 

 another in the most complicated manner, as in the skin and 

 mucous membranes. Fibrous tissue may be studied in the 

 fresh state, or after maceration, or in hardened preparations. 

 To examine the tissue in the fresh state it is best to make a 

 preparation of a tendon by teasing. A small tendon (such as, 

 e. (/., one of the extensors of the toes) having been cut out from 

 a recently killed frog or rabbit, is placed from ten to fifteen 

 minutes in a five to ten per cent, solution of chloride of sodium, 

 whereb}'- the splitting of the tendon is considerably facilitated. 



Process of Teasing. In making preparations b}- teasing, 

 the following practical rules must be attended to: A very small 

 portion must be used; this must be placed on the glass in a 

 drop of the liquid to be employed, which must also be small, 

 for if in too great quantity the particles teased out, swim away 



