52 



MICROSCOPY FOR BEGINNERS. 



Fig. 8. Whorl of Myriophyllnm 

 Leaves. 



set is arranged in a circle around the stem ; they are in 

 "whorls," as the botanist calls the arrangement. One 

 such whorl is shown in Fig. 8. Five dissected leaves 

 are there drawn, but whorls 

 sometimes occur with three 

 or four, the number helping 

 to distinguish the species, 

 of "which there are several. 

 They all resemble one anoth- 

 er when in the water. The 

 parts of the leaf are fine, 

 soft, and hair-like, those near- 

 est the stem of the plant 

 being the longest. They are 

 very numerous and close to- 

 gether, thus giving the floating streamers their pecul- 

 iar thick and soft appearance, and making them an ex- 

 cellent place for the microscopist to explore. 



To compare with Fig. 8 a feathery plant which the 

 collector does not know, select a circle of leaves, cut the 

 stem close above and below it, and after floating the 

 separated whorl in a saucer as already directed, or spread- 

 ing it out on white paper, compare its leaves with those 

 figured. The leaves vary in size in different parts of 

 the plant, the uppermost being smallest and youngest, 

 the lower the oldest arid largest. 



There is another rather common aquatic plant called 

 Proserpindca, or " mermaid- weed," which so closely re- 

 sembles Myriophyllum when in the water that it has 



