THE MORrHOLOGICAL COMPOSITION OF PLANTS. 71 



that the general relations are as described, and that they are 

 such as the hypothesis leads us to expect. Nor are 



^Ye without a kindred explanation of certain remaining traits 

 of foliar organs in their least- developed forms. Petals, 

 stamens, pistils, &c., besides reminding us of th.e primordial 

 fronds by their diminished sizes, and by the want of those 

 several supplementary parts which, the preceding segments 

 possess, also remind us of them by their histological charac- 

 ters : they consist of simple cellular tissue, scarcely at all 

 differentiated. The fructifying cells, too, which here make 

 their appearance, are borne in ways like those in which the 

 lower Aero gens bear them — at the edge of the frond, or at 

 the end of a peduncle, or immersed in the general substance ; 

 as in Figs. 128 and 129. Nay, it might even be said that 

 the colours assumed by these terminal folia, call to mind the 

 plants out of which we conclude that Phaenogams have been 

 evolved ; for it is said of the fronds of the JungermanniacecEf 

 that "though under certain circumstances of a pure green, 

 they are inclined to be shaded with red, purple, chocolate, or 

 other tints." 



As thus understood, then, the homologies among the parts 

 of the phaenogamic axis are interpretable, rot as due to a 

 needless adhesion to some typical form or fulfilment of a pre- 

 determined plan ; but as the inevitable consequences of the 

 mode in which the phaenogamic axis originates. 



§ 197. And now it remains only to observe, in confirmation 

 of the foregoing synthesis, that it at once explains for us 

 various irregularities. When we see leaves sometimes pro- 

 ducing leaflets from their edges or extremities, we recognize 

 in the anomaly, a resumption of an original mode of growth : 

 fronds frequently do this. When we learn that a flowering 

 plant, as the Brosera intermedia, has been known to develop 

 a young plant from the surface of one of its leaves, we are at 

 once reminded of the proliferous growths and fructifying 

 organs in the Liverworts. The occasional production of bul- 



