74 PRACTICAL HISTOLOGY. 



The fibres refract the light strongly, and therefore have 

 a distinct dark border. They branch and form an anasto- 

 mosing network. Their ends may be curled or straight 

 The fibres under examination are a very coarse variety, 

 being about the breadth of a blood corpuscle. In the 

 vocal cords and in areolar tissue generally, they are much 

 finer. This preparation may be preserved in Farrants' 

 solution or glycerine ; in the last, however, the borders of 

 the fibres are not nearly so dark, owing to the high refrac- 

 tive index of the medium. 



100. Areolar Tissue (H.) a. Rapidly spread out 

 with needles on a dry slide a small piece of subcutaneous 

 tissue from a cat or rabbit. A dry slide is taken in order 

 that the tissue may adhere to it, and so be spread out 

 readily. The tissue must not, however, be allowed to dry. 

 Add salt solution and examine. Notice that the white 

 fibres consist of bundles of fibrils. The borders of the 

 white fibres are faint and ill defined. An elastic fibre may 

 be found here and there in the field ; unlike the white fibre, 

 its margin is sharply defined, owing to its substance being 

 strongly refractile. 



b. Remove the cover-glass and add acetic acid. It 

 causes no change in the elastic fibres, but the white fibres 

 swell up, the fibrils disappear, and nothing marks their posi- 

 tion excepting a clear jelly. The nuclei of the connective 

 tissue corpuscles are brought into view. Areolar tissue may 

 be preserved in potassium acetate or weak spirit. Glycerine 

 causes the white fibres to swell up and become transparent 

 or hyaline. This preparation .need not, however, be pre- 

 served, as specimens will be obtained in sections of the 

 alimentary canal. 



The splitting of the white fibres into fibrils is very easily effected 

 after maceration for a fortnight or so in a 10 per cent solution of 

 sodium chloride, often changed, or in lime or baryta water. (Rollett. ) 

 These agents appear to soften or dissolve a cement which unites the 

 fibrils. 



White fibrous tissue may be dissolved by boiling in water ( 285) or 

 dilute sulphuric acid ( 286), and may be softened by maceration in 

 dilute alcohol ( 284). 



1 01. (H.) Examine a preparation of intermuscular 



