48 



HOBSB AXD MAX. 



snb-lamimi3, while now arid then one of them throws 

 off a branch similarly furnished with sub- lamina. 

 The colours which are presented by these structures 

 under polarised light are beyond the power ot 





APPEARANCE OF HORN- 

 FIBRES BY POLARISED 

 LIGHT. 



TWO LAMINA WITH THEIR SUB-LAMINAE. 



description. I have, however, endeavoured to give 

 some idea of them without the aid of colour. 



One other point remains to be mentioned in 

 connection with this part of the subject. This is 

 the ' linea alba,' or white line, which marks the 



