49© PHANEROGAMS. 



cases of apparent dichotomy, there are in Angiosperms only a few cases of actual or 

 apparent extra-axillary branching, which will be mentioned when discussing the 

 characteristic features of this class. 



Phanerogams are distinguished from Cryptogams by an extraordinarily varied 

 and complete metamorphosis of members bearing the same name ; and this is con- 

 nected with the almost infinite variety in the mode of life, and the more marked 

 differentiation of the physiological functions of these plants; and the same is the 

 case with the differentiation of tissues, which in Phanerogams greatly exceeds even 

 that of Ferns. In these respects also Gymnosperms assume an intermediate 

 position between Cryptogams and the rest of Phanerogams. 



What has now been said will serve to explain on one hand the distinction between 

 Vascular Cryptogams and Phanerogams, on the other hand the points in which they 

 agree, and the affinity of the two groups in their main outlines. In order, however, to 

 facilitate the comprehension by the student of the characteristics of the separate classes 

 of Phanerogams which are now to be described, we must in the first place keep in 

 view a few of their peculiarities, which have at present only been briefly touched upon, 

 and attempt to settle the nomenclature, which has become to some extent obsolete 

 and out of harmony with the most recent theories. 



The Floiver, in the broadest sense of the term, is composed of modified foliar organs 

 and of an axis which bears them. [The most highly modified leaves of the flower are 

 the stamens and the carpels : these so-called ' sexual organs ' are really spore-bearing 

 organs, comparable to the spore-producing leaves of the Vascular Cryptogams.] When 

 the leaves which stand immediately beneath the sexual organs on the same axis differ 

 from the rest of the leaves of the plant in their arrangement, form, colour, or structure, 

 and are physiologically connected with fertilisation and its results, they are considered as 

 belonging to the flower, and are termed collectively the Floral Leaves or Perianth, 

 The separate flowers are distinguished from the Inflorescence by including, together 

 with their sexual organs and perianth, only one axis, while the inflorescence is an axial 

 system with more than one flower ^ Roper has termed the tout ensemble of the male 

 sexual organs of a flower the Andrcecium, that of the female organs the GyncBceum, 

 When a flower contains sexual organs of both kinds it is called hermaphrodite or bisexual; 

 if it contains only male or only female sexual organs, and is therefore unisexual^ it is termed 

 diclinous; when flowers of both sexes occur on the same individual plant, the species 

 is moncEcious, when on different individuals it is dioecious. Usually the apical growth 

 of the floral axis ceases as soon as the sexual organs make their appearance, and fre- 

 quently even earlier ; the apex of the floral axis is then concealed, and is often deeply 

 depressed in the centre of the flower ; but in abnormal cases (and normally in Cycas) the 

 apical growth of the floral axis re-commences, again produces leaves, and sometimes 

 even a new flower, and a Proliferous Flo'^ver is thus produced. The sexual organs 

 and perianth of a flower are usually crowded (arranged in rosettes either spirally or 

 in whorls) ; the part of the floral axis which bears them remains very short, no inter- 

 nodes being in general distinguishable in it ; and it not unfrequently expands into the 

 form of a club or disc, or becomes hollow, and this part of the floral axis is called the 

 Torus or Receptacle. In Coniferae and Cycadeae (occasionally also in Angiosperms), it 

 is however sometimes elongated to such an extent that the sexual organs appear loosely 

 arranged along an axis in the form of a spike. Beneath the receptacle the axis is mostly 



* In some cases it is hov^^ever difficult to distinguish between a flower and an inflorescence; 

 as in some Coniferse, and especially in Euphorbia. {On the latter, see Warming in Flora, 1870, 

 no. 25 ; Schmitz, do. 1871, nos. 27, 28; and Hieronymus, Bot. Zeitg. 1872, no. 12.) [E. Waiming, 

 Er Koppen hos Vortemaelken en Blomst eller en Blomsteistand, Kobenhavn 1871.] 



