174 crOger's organographical observations 



it seems to me as though the development and character of this 

 organ might throw some light over this subject, although analo- 

 gies, often only apparent, cannot wholly decide such a question. 

 When, for instance, in agreement with their mode of development 

 and their arrangement, we regard the two calli which occur under 

 the stigma as the points of two carpels, the tube which leads to 

 the germen is formed only on the outer carpel, and indeed, as it 

 seems, on the back of it. It may be equally assumed in the 

 Orchideae, that the canal of the stigma is developed in that 

 carpel falling next the bract, while the other two, lying next the 

 labellum, may be supposed to be buried in this, which at the 

 same time gives a kind of explanation of the frequent resem- 

 blance between the labellum and the column. Of course the 

 many arms and branches of the latter remain unexplained here, 

 unless we consider that this is itself a complex organ. The 

 mode of dehiscence of the capsule of the Orchideae favours the 

 view which assumes six instead of three carpels in this family, 

 and the loculicidal dehiscence is likewise analogous to that most 

 frequent in the groups nearest allied to the Orchideae. It is 

 worthy of observation in the Bromeliaceae, that in the genera 

 which have a dry fruit, sometimes the loculicidal, sometimes the 

 septicidal dehiscence occurs, according as the fruit is blended 

 with the circles of organs surrounding it, or is possessed of a free 

 superior ovary. Among the Orchideae, the fruits of Cryptar- 

 rhcena lanata, R. Br. ; Dichcea graminoideSy Lindl. ; and certain 

 species of Pleurothallis, open on one side, i. e. two valves 

 standing at the side of the column remain connected together, 

 and the third, which stands below the labellum, separates from 

 the others by two fissures. The ribs, which in other species 

 separate from the placentiferous valves, are entirely wanting 

 here. It would seem as if the firmer combination of the valves 

 below the column, in these cases, was produced by the stamen 

 occurring above them. But it must not be forgotten that in all 

 these cases the septa, or in one-celled fruits the placentas, alter- 

 nate with the sepals. 



The mode, however, in which a fruit bursts, cannot prove any- 

 thing concerning its morphological nature. The great variation 

 which prevails in this phaenomenon, the circumstance that 

 otherwise very nearly allied genera exhibit essential differences 



