HISTOLOGICAL DEMONSTRATIONS. 77 



wood ( 323) and mounted in Farrants^ solution, or in 

 glycerine. 



Rows of flattened cells (Ranvier's cells) will be seen 

 lying between the longitudinal bundles of fibres. The cells 

 are somewhat quadrangular plates consisting of a distinct 

 nucleus surrounded by granular protoplasm. Their relation 

 to the fibres has been the subject of considerable dispute. 

 In a piece of tendon stained with gold and successfully 

 teased with needles, one may see, as Boll first pointed out 

 (Schultze's ArchiVj 1871, p. 281), that the cells clasp the 

 bundles and apparently extend about half-way round them. 

 A longitudinal stripe in the row of cells was pointed out by 

 Boll, and termed $ by him the "elastic stripe." More than 

 one stripe may be seen in each row. A view in full face of 

 the margin of a cell has the appearance resembling Boll's 

 stripe. Ranvier has shown, however (Traite Technique 

 d'Histologie, p. 352), that Boll's stripes are due to ridges on 

 the cells ; such a ridge as that seen on a bent tile or plate 

 of zinc on the top of a house. 



107. For the demonstration of these ridges and the isolation of 

 tendon cells, Ranvier (loc. cit. ) recommends the following : Place a 

 tendon for twenty-four hours in I per cent osmic acid, and then for the 

 same period in picro-carmine. Endeavour to isolate the tendon cells by 

 teasing with needles, and examine in glycerine containing I per cent 

 formic acid. 



1 08. Adipose Tissue (H). Examine the preparation 

 of omentum of guinea-pig or cat already made ( 870). 

 Observe the shapes of the fat cells when they are isolated, and 

 when they are pressed one against another. The nucleus of 

 the fat cell may have been stained by the silver, and if so, it 

 will be readily seen, especially if a profile view be obtained. 

 The nucleus is also rendered evident by carmine or logwood 

 staining. Each cell consists of a thin membrane more or 

 less filled by a drop of fat, having a nucleus with a small 

 quantity of protoplasm in contact with the membrane at 

 one part of the cell. Fat cells when silvered and mounted 

 in Farrants' solution or in glycerine are very perfectly pre- 

 served. 



109. The envelope of the fat cell may be readily shown by the 



