THE PRINCIPAL TISSUES. 



75 



To examine fibrous tissue it is only necessary to make thin longitudi- 

 nal slices of the stems of woody plants e.g., Acer, Pirus, etc. and to 

 heat for a minute or less in nitric acid and potassium chlorate. The 



FIG. 64. 



PIG. 65. 



Fig. 64. Laticiferous tubes from Euphorbia. A. moderately magnified; -B, more 

 highly magnified, and showing the bone-shaped or dumb-bell-shaped starch grains. 

 After S;icli!*. 



Fig. 65. Laticiferous vessels of Scorzonera, hispanica. A, a transverse section of 

 the phloem of the root ; B. the same more highly magnified. After Sachs. 



fibres may now be separated under a dissecting 1 microscope, or the 



cases at least, the fibres are not cell-derivatives, and the partitions the 

 persistent walls of the original component cells. 



