[109] 



1baIf:^an:«»1bour at tbe fllMcroacope, 



mitb /iDr^ Zixttcn Mest, f.%.S., ff^lR^/UbS^ etc» 



Plates 27 — 31. 



Yucca recurva (PI. 27, Figs, i — 7). — Yucca belongs to the 

 LiliacecE^ an extensive and important natural order, which in- 

 cludes plants of very diverse appearance and use, as Hyacinths, 

 Tulips, Onions, Aloes, Asparagus, Australian " Grass-Tree," etc. 

 In 1861, three species of Yucca were cultivated in this country; 

 that which is most frequently met with is the Yucca gloriosa, or 

 " Adam's Thread and Needle," of which magnificent specimens 

 were to be seen growing in the Crystal Palace grounds. The 

 section before us shows various points well. It has been taken 

 from a striped variety, if I read correctly the blanched look of the 

 cell-contents at the angles of the leaf The arrangement of the 

 woody bundles will be noticed as interesting. Those next the 

 surface furnish an example of " liber-fibre" ; were it procurable in 

 sufficient quantity a strong cordage might be made of this. A 

 member of the family, the " New Zealand Flax," has of late years 

 come prominently into notice as furnishing such a material, which 

 is largely used in the manufacture of string. We have before us 

 also a good example of thickening of cuticle by external cell- 

 formation ; sections of stomata, showing the openings and the 

 cells which regulate the extent of aperture ; of papillar cuticle ; of 

 raphides in situ, etc. etc. 



Clematis, trans, section (PI. 27, Figs. 8, 9). — The species 

 whence this section has been made is not stated ; in the absence 

 of information on the point we must suppose it to be from C. 

 vitalba, the " Traveller's Joy," an elegant native, which luxuriates 

 in chalky districts, and is especially beautiful, with its heads of 

 feathery fruit in the winter-time, when all else is bare. It may be 

 seen thus in its glory near Niton in the Isle of Wight ; on the 

 Hog's Back and Reigate Hill in Surrey, etc. Clematis belongs to 

 the RanunculacecB. The section before us illustrates a condition 

 not very common in plants, — the growth of a distinct layer of 

 Uber-fibres with every season. In many climbing-plants, it is 

 common for the bark to split into layers, which hang in regular 

 shreds. The Woodbine and Vine show this well; the tendency to 



