SIGNS USED IN THIS WORK. 



° \ ". The sign of degrees (°) is used for feet ; of minutes ('), for inches ; 

 of seconds ("), for lines, — the line being the twelfth part of an inch, and very- 

 near ly equivalent to two millimetres. 



)tt. In microscopic measurements, the conventional sign for the micromilli- 

 metre or the one-thousandth part of a millimetre = one two-thousandth part of 

 a line. 



$ Bearing only stamens or antheridia. 



9 Pistillate or bearing archegonia. 



1 A mark of doubt. 



! A mark of affirmation or authentication. 



Figures or words separated by a short dash (-) indicate the extremes of 

 variation, as "5-10" long, few - many-flowered," i. e. varying from 5 to 10 

 lines in length, and with from few to many flowers. 



