46 MORPHOLOGICAL DEVELOPMENT. 



I say a proximate interpretation, because there remain to 

 be solved certain deeper problems; one of which at once 

 presents itself to be dealt with under the present head. 

 Leaves, petals, stamens, &c., being shown to be homologous 

 foliar organs; and the part to which they are attached, 

 proving to be an indefinitely-extended axis of growth, or 

 axial organ; we are met by the questions, What is a foliar 

 organ ? and What is an axial organ ? The morphological com- 

 position of a Phaenogam is undetermined, so long as we can- 

 not say to what lower structures leaves and shoots are homo- 

 logous; and how this integration of them originates. To 

 these questions let us now address ourselves. 



190-1. Already, in 78, reference has been made to the 

 occasional development of foliar organs into axial organs: 

 the special case there described being that of a fox-glove, in 

 which some of the sepals were replaced by flower-buds. 

 The observation of these and some analogous monstrosities, 

 raising the suspicion that the distinction between foliar 

 organs and axial organs is not absolute, led me to examine 

 into the matter; and the result has been the deepening of 

 this suspicion into a conviction. Part of the evidence is given 

 in Appendix A. 



Some time after having reached this conviction, I found on 

 looking into the literature of the subject, that analogous ir- 

 regularities had suggested to other observers, beliefs similarly 

 at variance with the current morphological creed. Diffi- 

 culties in satisfactorily defining these two elements, have 

 served to shake this creed in some minds. To others, the 

 strange leaf-like developments which axes undergo in certain 

 plants, have afforded reasons for doubting the constancy of 

 this distinction which vegetal morphologists usually draw. 

 And those not otherwise rendered sceptical, have been made 

 to hesitate by such cases as that of the Nepaul-barley, in 

 which the glume, a foliar organ, becomes developed into an 

 axis and bears flowers. In his essay "Vegetable Morph- 



