Chap. XIII. 



EEVEKSION. 



therefore, to a certain extent, in a rudimentary state ; the pistil is curved 

 towards the perfect nectary, and the hood, formed of the inner petals, 

 slips off the pistil and stamens in one direction alone, so that, when a bee 

 sucks the perfect nectary, the stigma and stamens are exposed and rubbed 

 against the insect's body. In several closely allied genera, as in Dielytra, 

 &c, there are two perfect nectaries, the pistil is straight, and the hood 

 slips off on either side, according as the bee sucks either nectary. Now, 

 I have examined several flowers of Corydalis tuberosa, in which both nec- 

 taries were equally developed and contained nectar ; in this we see only 

 the redevelopment of a partially aborted organ ; but with this redevelop- 

 ment the pistil becomes straight, and the hood slips off in either direction ; 

 so that these flowers have acquired the perfect structure, so well adapted 

 for insect agency, of Dielytra and its allies. We cannot attribute these 

 coadapted modifications to chance, or to correlated variability; we must 

 attribute them to reversion to a primordial condition of the species. 



The peloric flowers of Pelargonium have their five petals in all respects 

 alike, and there is no nectary; so that they resemble the symmetrical 

 flowers of the closely allied Geranium-genus ; but the alternate stamens 

 are also sometimes destitute of anthers, the shortened filaments being left 

 as rudiments, and in this respect they resemble the symmetrical flowers of 

 the closely allied genus, Erodium. Hence we are led to look at the peloric 

 flowers of Pelargonium as having probably reverted to the state of some 

 primordial form, the progenitor of the three closely related genera of 

 Pelargonium, Geranium, and Erodium. 



In the peloric form of Antirrhinum rnajus, appropriately called the 

 " Wonder," the tubular and elongated flowers differ wonderfully from 

 those of the common snapdragon ; the calyx and the mouth of the corolla 

 consist of six equal lobes, and include six equal instead of four un- 

 equal stamens. One of the two additional stamens is manifestly formed 

 by the development of a microscopically minute papilla, which may be 

 found at the base of the upper lip of the flower in all common snap- 

 dragons, at least in nineteen plants examined by me. That this papilla 

 is a rudiment of a stamen was well shown by its various degrees of deve- 

 lopment in crossed plants between the common and peloric Antirrhinum. 

 Again, a peloric Galeobdolon luteum, growing in my garden, had five equal 

 petals, all striped like the ordinary lower lip, and included five equal 

 instead of four unequal stamens ; but Mr. E. Keeley, who sent me this 

 plant, informs me that the flowers vary greatly, having from four to six 

 lobes to the corolla, and from three to six stamens. 69 Now, as the mem- 

 bers of the two great families to which the Antirrhinum and Galeobdolon 

 belong are properly pentamerous, with some of the parts confluent and 

 others suppressed, we ought not to look at the sixth stamen and the sixth 

 lobe to the corolla in either case as due to reversion, any more than the 

 additional petals in double flowers in these same two families. But the 

 case is different with the fifth stamen in the peloric Antirrhinum, which 



69 For other cases of six divisions in peloric flowers of the Labiate and 

 Scrophulariacese, see Moqnin-Tandon, ' Teratologic,' p. 192. 



