MUTUAL ACCOMMODATIONS BETWEEN PLANT ORGANS. 



159 



assume the characters of an inner one, or vice versa, respectively. 

 A few illustrations will explain this. 



In Hydrangea and Fuchsia the calyx is normally petaloid, 

 but in the " cup-and-saucer " campanulas, and " hose-in-hose " 

 Mimulus, the calyx has abnormally acquired all the features of a 

 corolla. In water-lilies the transition between petals and stamens 

 is normally characteristic, while in a monstrous foxglove I once 

 noticed the corolla was split up into stamens. In the "rogues" 

 among wall-flowers, and in poppies and oranges, the stamens 

 often become abortive carpels, while begonias are particularly 

 liable to produce all sorts of mixtures between staminate and 

 pistillate structures. 



Retrogression is seen in carpels and ovules becoming more 

 or less of a staminate character, as in willows, and in roses, &c, 

 described by Dr. Masters in his " Teratology." Sometimes ovules 

 become petals, as is not infrequent in lady's smock (Cardamine 

 pratensis), and in a rhododendron received from Mr. Veitch. 

 Sometimes they become foliaceous, as in a mignonette described 

 by the late Professor J. S. Henslow. Stamens, as well as carpels, 

 turn into petals, as in complete double flowers, and then become 

 multiplied. A further retrogression is seen in their becoming 

 foliaceous, as the pistil of the double cherry, the green rose, the 

 alpine strawberry, &c. In forms of primroses, the corolla alone, 

 or the sepals only, may turn into leaves. Since it thus appears 

 that all the organs of a flower are but leaves in another form, a 

 flower-bud is therefore homologous with a leaf-bud ; and as the 

 latter can develop into an elongated branch with leaves, or else 

 assume the abbreviated form with leaf- scales, as of a bulb, so can 

 a flower-bud become replaced by either one or the other ; the 

 axis not infrequently elongating in roses, or forming bulbils in 

 place of flowers in onions. 



Lastly, minute bracts, as of plantains, may grow out into 

 true leaves, thereby revealing their homology. The general 

 practical result issuing out of these phenomena, is that if Nature 

 shows any sign of departure from the normal structure of an 

 organ in a flower or elsewhere, the horticulturist has it in his 

 power to encourage the change, and, it may be, ultimately to fix 

 it if it be desirable to do so. Thus the whole of the balsamrcflora 

 section of the E. I. Rhododendrons raised by Mr. J. Heal for 

 Messrs. Veitch were secured by his detecting a slightly petaloid 



