356 THE M1CEOSCOPE. 



subject; and published an excellent paper in the Micro- 

 scopical Society's Transactions, 1840 ; the results of has 

 observations on the development of vascular tissue. 



1 Fig. 189. 



1, Interior cast of the siliceous portion of spiral tubes of the Opuntia. 2, Vertical 

 section of Elm, showing spiral fibre. 



In order to watch the development of the membranous 

 tnbes of plants, no better example can be chosen than the 



Fig. CO. 



A transverse section of Taxus baceata (Yew), showing the woody fibra 

 J, Vertical section of tbe Yew, exhibiting pores and spira) fibres. 



