The Classes are distinguished from each other in this ingenious system, by the number, situation, adhesion, or reciprocal proportion of the males in each flower. The Orders, in many of these Classes, are distinguished by the number, or other circumstances of the females. The Families, or Genera, are characterized by the analogy of all the parts of the flower or fructification. The Species are distinguished by the foliage of the plant; and the Varieties by any accidental circumstance of colour, taste, or odour; the seeds of these do not always produce plants similar to the parent; as in our numerous fruit-trees and garden flowers; which are propagated by grafts or layers. The first eleven Classes include the plants, in whose flowers both the sexes reside; and in which the Males or Stamens are neither united, nor unequal in height when at maturity; and are therefore distinguished from each other simply by the number of males in each flower, as is seen in the annexed PLATE, copied from the Dictionaire Botanique of M. BULLIARD, in which the numbers of each division refer to the Botanic Classes. CLASS I. ONE MALE, _Monandria_; includes the plants which possess but One Stamen in each flower. II. TWO MALES, _Diandria_. Two Stamens. III. THREE MALES, _Triandria_. Three Stamens. IV. FOUR MALES, _Tetrandria_. Four Stamens. V. FIVE MALES, _Pentandria_. Five Stamens. VI. SIX MALES, _Hexandria_. Six Stamens. VII. SEVEN MALES, _Heptandria_. Seven Stamens. VIII. EIGHT MALES, _Octandria_. Eight Stamens. IX. NINE MALES, _Enneandria_. Nine Stamens. X. TEN MALES, _Decandria_. Ten Stamens. XI. TWELVE MALES, _Dodecandria_. Twelve Stamens. The next two Classes are distinguished not only by the number of equal and disunited males, as in the above eleven Classes, but require an additional circumstance to be attended to, _viz._ whether the males or stamens be situated on the calyx, or not. XII. TWENTY MALES, _Icosandria_. Twenty Stamens inserted on the calyx or flower-cup; as is well seen in the last Figure of No. xii. in the annexed Plate. XIII. MANY MALES, _Polyandria_. From 20 to 100 Stamens, which do not adhere to the calyx; as is well seen in the first Figure of No. xiii. in the annexed Plate. In the next two Classes, not only the number of stamens are to be observed, but the reciprocal proportions in respect to height. XIV. TWO POWERS, _Didynamia_. Four Stamens, of which two are lower than the other two; as is seen in the two first Figures of No. xiv. XV. FOUR POWERS, _Tetradynamia_. Six Stamens; of which four are taller, and the two lower ones opposite to each other; as is seen in the third Figure of the upper row in No. 15. The five subsequent Classes are distinguished not by the number of the males, or stamens, but by their union or adhesion, either by their anthers, or filaments, or to the female or pistil.