TRANSFORMATION OF SPOROPHYLLARY. 179 



presented itself especially in the case of PodopJiyllnni pcltatiim, 



Arisccvia tripJiylhim, and Aralia midicaiilis. In Geraniiivi 



maculatii7n, Sniilacina racemosa, Angelica atroptirpurea, and 



Veratriim viride the sporophyllary organs were too far advanced. 



While direct experimental evidence seems to be lacking, 

 there is enough of empirical evidence to show that the trans- 

 formation of the sporophyllary organs to vegetative ones takes 

 place quite frequently in certain species of the phanerogams. 



Transformations of the andraecium, or stamens (microsporo- 

 phylls), is not a very common occurrence, though it is recorded 

 in the case of several species. Petunia, Jatropha pohliana Miill. 

 (Miiller, Mem. Soc. Phys. et Hist. Nat., Geneva, Tome XVII), 

 Trifoliiim i'epens, cultivated species of Rosa, etc. Transforma- 

 tions of the pistils, or gynaecium (macrosporophylls), are much 

 more common and remarkable. In the double-flowering cherry 

 the ovary is changed often to a small foliar organ, frequently 

 the margins separated thus exposing the ovules, while the tip 

 has a slender style and imperfect stigma. Moquin relates a 

 case in a tulip where the ovary was represented by true leaves 

 with ovules on their margins. This frequently happens in the 

 columbine and in members of the Cruciferae and Umbelliferae. 

 In Vitis sometimes the pistil is foliaceous, with the ovules on 

 their inner surface (Planchon et Mares, Ajdi. Sci. Nat., Ser. 5, 

 Tome VI, p. 228, 1866). If the ovary is the homologue of the 

 macrosporophyll in the strobilus of the Archegoniatae, as Bower 

 suggests, then the opening of the ovary and the exposure of 

 the ovules, or macrosporangia, under the influence of changed 

 or disturbed conditions of nutrition, must be looked upon as a 

 partial reversion inform only, not a reversioji in function. This 

 is accompanied by a more or less complete sterilization of the 

 sporogenous tissue, the expansion of the blade into a well- 

 developed foliar organ, and the assumption of the vegetative 

 function in place of the reproductive one. 



The philosophy of these changes, viewed not only in the light 

 of immediate causes, but also from the standpoint of phylogeny 

 of the foliar organs of the sporophyte, teaches that they proceed 

 from the sporophyllary to the vegetative organs. This study 

 has led rather unexpectedly to questions of deeper import than 



