290 THE FLOWER. 



their nature and symmetry, and their principal modifications as to 

 relative number and disposition. Their absolute number in the 

 flower, it may be remarked, is designated by Greek numerals pre- 

 fixed to the word used for stamens, as employed by Linnaeus in the 

 names of his artificial classes. Thus, a flower with one stamen is 

 said to be monandrous ; with two, diandrous ; with three, irian- 

 drous ; with four, tetrandrous ; with five, pentandrous ; with siv, 

 hexandrous ; with seven, heptandrous ; with eight, octandrous ; 

 with nine, enneandrous ; with ten, decandrous ; with twelve, 

 dodecandrous ; and with a greater or indefinite number, polyan- 

 drous. (See the account of the classes of the Linnaean Artificial 

 System, in Part II.) 



518. The terms employed to designate their various modifica- 

 tions, most of which have already been incidentally noticed, are 

 likewise derived from the names of Linnsean artificial classes, with 

 the exception of those which relate to their insertion ; namely, as 

 hypogynous, when inserted on the receptacle (466), or, in other 

 words, free from all adhesion to neighbouring organs ; perigynous, 

 when adherent to the tube of the calyx (as in Fig. 315) ; and epi- 

 gynous, when adherent also to the ovary, and, as it were, raised 

 to its summit (as in Fig. 316). To these may be added the Lin- 

 nsean term gynandrous, expressive of their further cohesion with 

 the style, as in the Orchis Family (Ord. Orchidacese). 



519. As to mutual cohesion, they are monadelphous when united 

 by their filaments into one body (as in Fig. 307) ; diadelphous, 

 when thus combined in two sets (as in Fig. 308) ; triadelphous, 

 when in three sets, as in Hypericum and Elodea (Fig. 300, 301) ; 

 pentadelphous, when in five sets, as in our Linden ; .and polyadel- 

 phous, when in several sets, irrespective of the particular number. 

 They are syngenesious, when united by their anthers (Fig. 309, 

 310). As respects inequality of size, they are didynamous, when 

 four stamens constitute two pairs of unequal length (481) ; and 

 tetradynamous, when six stamens only are present, two of which 

 are shorter than the others, as in Cruciferous flowers (455) ; a 

 case which is sometimes, but less distinctly, seen in the allied Caper 

 Family (Fig. 352). Their complete suppression in some flowers 

 gives rise to such terms as monoecious, dioecious, and polygamous, 

 which have already been defined (473). 



520. The proportion of the stamens to the corolla or other floral 

 envelopes is sometimes to be noticed. When they are longer and 



