THE PMINGIPAL TISSUES. 



75 



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

 nal 8lic<'S f f 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. 



Fig. 65. 



Fig. 64.— Laticifernus tubes from SwpAorftia. >!. miderately magnifiecl; S. more 

 higliTy magnified, and showing the hone-shaped or dumb-bell-shaped starch grains. — 

 After Snchs. 



Fig. 65. — liflticiferons vessels of Scorzonera hisparnna. A, a transverse section of 

 the phloSm of the root ; B. the same more highly magnified.— Alter Sachs. 



fibres may now he separated under a dissecting microscope, or the 



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

 persistent walls of the original component cells. 



