36 



HUTCHINSON'S POPULAR BOTANY 



The fibrous spirals in the leaf-cells of many Cone-bearing plants (Coniferce) 

 have been pressed into the service of man, being found to afford an excellent 

 substitute for wool and cotton. In 1842 a quantity of woven fabric of this 

 material was introduced in place of cotton in the hospital at Vienna, where, 

 after several years' experiment, it was renewed. Similar success attended 

 its introduction into prisons and hospitals at Berlin, Breslau, and other 

 places. When used in mattresses, it is found to last three times longer than 

 wool ; while for spinning and weaving purposes it has the strength of hemp, 



Photo by] 



FIQ. 59. MISTLETOE (Viscum album). 



[K. Step. 



The well-known shrub that grows on various trees, chiefly Apple, parasitically. The possession of leaves, how- 

 ever, shows that it is not wholly a parasite. One-third of natural size. EUROPE, N. ASIA. 



and so may be profitably employed in the manufacture of carpets and 

 blankets. 



Sometimes the thickening of the cell-walls takes the form of rings, as in 

 the Mistletoe ( Viscum album) and many grasses ; and thus we get annular 

 cells a name derived from the Latin annulus, a ring (fig. 57). Three or 

 four indiarubber rings fitted tightly in a short cylindrical lamp-glass give 

 the idea. Not infrequently the rings appear to have their beginning in 

 spiral fibres, which, in consequence of their rapid growth, get broken in 

 places, and so fall together in rings ; indeed, the transition from the spiral 

 to the ringed form has been observed in certain plants, notably in the 



