MICROSCOPIC OBJECTS. 17 



Fig. 33. Simple Form of Hair from the Cabbage (Brassica 

 oleracea), x 120. 



The simple form of hair is very common on plants, although 

 perhaps not more so than the ordinary straight compound 

 hairs (see fig. 28) . The hairs consisting of only one cell 

 makes it an easy matter to distinguish, under a moderately 

 low power of the microscope, say a ^-inch, the compound 

 hairs with their knobbed cells of the true Tobacco, from the 

 adulterations with cabbage-leaves &c., most of which have 

 only simple forms of hairs. 



These hairs, together with most vegetable hairs, are best 

 when mounted in liquid. 



Fig. 34. Compound Beaded Hair from a Stamen of 

 Tradescantia, x 200. 



This compound hair has been drawn to illustrate another 

 form that hairs sometimes take, viz. the beaded form. They 

 are to be found on the common Groundsel, Sow-thistle, and 

 other plants. In fact, on the Sow-thistle they are sometimes 

 so numerous as to give that plant a hoary or frosted appear- 

 ance. 



For other forms of compound hairs, see figs. 28, 29, 30, 31, 

 &c. Hairs of plants are sometimes developed into the form 

 of stings (see fig. 35). 



These beaded hairs may be mounted dry or in fluid. 



