SPIRAL VESSELS. 39 



microscope ; wet it with water ; and then lay over it 

 another flat piece of glass. Press the two glasses 

 firmly together, and by degrees you will squeeze all 

 the air out of the petal, and it will become transparent. 

 You may then, with a pretty good magnifs'ing power, 

 observe all the air-vessels of the veins distinctly, 

 looking like fine threads of silver wire twisted up 

 like a spiral spring. It is on account of this appear- 

 ance that the air-vessels are called technically spiral 



VESSELS. 



The stamens {fig. 2.) are ten, arising from beneath 

 the pistil ; that is, they are hypog^nous ; they are 

 placed in two rows, each of which consists of five sta- 

 mens. The lower part of the filament is broad, and 

 rather convex ; it curves a little towards the pistil, 

 and then tapers ofi^ into the part which bears the 

 anther. 



The pistil {fig. 3.) has a very singular appearance. 

 At the base it has five roundish projections, covered 

 all over with clammy hairs ; from the top of these 

 projections a sort of column arises, which at the 

 point is five-lobed {fig- 4.) ; the projections are the 

 ovaries, the column is composed of five styles glued 

 together, and the five lobes are the stigmas. The 

 hairs upon the ovaries will give you a good idea of 

 the nature of hairs in other plants. Cut off, with a 

 sharp knife, a very minute portion of the skin of one 

 of the ovaries, and lay the morsel on its side in 

 water under the microscope ; you will find that the 

 hairs are delicate transparent projections, tapering 

 to a point. Some of them are very short and 



