194 MISCELLANEOUS OBJECTIONS TO THE 



highly important nature, affecting only some of the flowers 

 on the same plant, or occurring on distinct plants, which 

 grow close together under the same conditions. As these 

 variations seem of no special use to the plants, they cannot 

 have been influenced by natural selection. Of their cause 

 we are quite ignorant ; we cannot even attribute them, as 

 in the last class of cases, to any proximate agency, suoh aa 

 relative position. I will give only a few instances. It is 

 so common to observe on the same plant, flowers inditfer 

 ently tetramerous, pentamerous, etc., that I need not givi 

 examples; but as numerical variations are comparatively 

 rare when the parts are few, I may mention that, accord 

 ing to De Candolle, the flowers of Papaver bracteatun, 

 offer either two sepals with four petals (which is the 

 common type with poppies), or three sepals with six petals. 

 The manner in which the petals are folded in the bud is, 

 in most groups, a very constant morphological character ; 

 but Professor Asa Gray states that with some species of 

 Mimulus, the aestivation is almost as frequently that of 

 the Rhinanthideae as of the Antirrhinidese, to which latter 

 tribe the genus belongs. Aug. Saint-Hilaire gives the fol- 

 lowing cases : the genus Zanthoxylon belongs to a division 

 of the Rutaceae with a single ovary, but in some species 

 flowers may be found on the same plant, and even in the 

 same panicle, with either one or two ovaries. In Helian- 

 themum the capsule has been described as unilocular or tri- 

 locular ; and in H. mutabile, " Une lame plus ou moins large 

 s'etend entre le pericarpe et le placenta." In the flowers of 

 Saponaria officinalis Dr. Masters has observed instances of 

 both marginal and free central placentation. Lastly, Saint- 

 Hilaire found toward the southern extreme of the range 

 of Gomphia oleaeformis two forms which he did not at first 

 doubt were distinct species, but he subsequently saw them 

 growing on the same bush ; and he then adds, " Voila done 

 dans un meme individu des loges et un style qui se rat- 

 tachent tantot a un axe verticale et tantot a un gynobase." 



We thus see that with plants many morphological changes 

 may be attributed to the laws of growth and the interaction 

 of parts, independently of natural selection. But with re- 

 spect to Nageli's doctrine of an innate tendency toward 

 perfection or progressive development, can it be said in 

 the case of these strongly pronounced variations, that the 

 plants have been caught in the act of progressing toward 

 ft higher state of development ? Ou the contrary, X should 



