1909] 



LEAVITT—HOMOEOSIS IN PLANTS 



41 



the carpel is marked by the same flexibility and miscibility of charac- 

 ters which pertains to the whole gynoecium. In ovaries affected by 

 the anomaly, but not yet resolved into separate carpellary leaves, 

 ovules become stalked, the integuments may compose a small cup 

 from the edge of which a few tentacles arise, or may be converted 

 into minute modified discoid or concave leaf-blades bearing numerous 

 minute tentacles. Between these blades, representing many charac- 

 ters of the radical leaves of the plant, and apparently perfect ovules, 



Similarly the stigmas 

 combine with their own 



many stages of gradation have been observed. 



most 



marginal 



fig 



tion of the calyx of Ranunculus bulbosus. The normal sepal A is 

 green and hairy on 

 the back, while the 

 petal is glabrous and 

 yellow. Sepals 5, C, 

 and D are progres- 

 sively invaded by 

 yellowness and glab- 

 rousness (and doubt- 

 less by other corolla Fig. 7. — Progressive homoeosis in sepals in Ranunculus 



characters), until in 



A 



D 



bulbosus. After 



all that remains of sepal nature is hairiness and slight greenness 

 m * e medi an line of the back. 



intermediate formations described here, which are of very 

 occurrence in plants, are the "anamorphoses" of Cela- 



common 

 kovsky. 



Migrating characters may transgress boundaries of 



term 



homologous," applied to organs supposed to have had 

 common evolutionary origin, is very often vague and not rarely is 



homology 



» « — "«5*v,oo im uiic icctbuii mat, wiiiie uegitreb ui 



ln mte > the specific degree of homology in many cases 

 ho\T n eVen approximatel y- In spite of this vagueness in the word, 



ovule 



• v «w*«w win prouaDiy agree mar me ovuie is m uu 



stam ^ ense the homologue of a shoot, nor yet of a pistil, nor of a 

 Cn ' nor of a foliage leaf, nor of the droseraceous tentacle. Yet 



