IO8 SHARP EYES 



named Equisetum, or "horse-tail." In place of seeds, it 

 perpetuates its kind by the aid of spores, which are 

 secreted in the fruit-like heads at the tips of the stems, 

 and when ripe are shed in clouds in the wind. Each 

 fruiting head is composed of a compact arrangement of 

 six-sided cells, and beneath each of these the spores are 

 formed. They float out like yellow dust upon every 

 passing breeze. But it is lively dust, indeed. Let us 

 pick this opening fruit, and shake a little of the powder 

 upon the glass of our pocket microscope. Upon look- 

 ing through the lens we see a myriad of motionless yel- 

 low spheres covering the field ; but in a moment it 

 becomes a wriggling, squirming mass of life, and in a 

 moment more the entire legion are jumping for free- 

 dom, and sailing off with their buoyant wings. A pinch 

 or so of the spores shaken in the hollow of the hand 

 appears like mere yellow powder ; but even with the 

 naked eye, after the lapse of a half-minute or so, it may 

 be seen to transform, gradually swelling to a bed of yel- 

 low downy fuzz, occupying several times the space of 

 the original powder. If a drop of water is allowed to 

 fall upon it, the fuzzy tuft appears to melt and contract; 

 and as the water evaporates, the same downy develop- 

 ment is repeated. A person seeing these squirming le- 

 gions in the microscope for the first time would cer- 

 tainly suppose he was looking upon the liveliest swarm 

 of living animalculse. Alive they certainly are; but, in 

 spite of appearances, the curious objects are mere vege- 

 table spores endowed with this singular faculty to in- 

 sure their propagation. When first seen upon the mi- 

 croscopic slide they appear as yellow spheres circled 

 with four small ridges; but as the whim takes them, 

 these ridges suddenly uncoil, and after a brief period of 



