THE LEAF. 



153 



foliage-leaves, in no way differing from those on other 

 parts of the plant either in size or complexity, as in 

 some Cruciferas, bnt are more usually much reduced 

 and scale-like in consistence. Under the stimulus of 

 excessive flow of nutriment or moisture the scale-like 

 bracts may develop congenitally into foliage-leaves 

 resembling those of the plant, as in the case of the 

 bracts subtending the spike of the plantain (Plantago 

 major and P. lanceolata) (PI. XII, figs. 1 and 2). Or 

 the bracts subtending all the flowers of the spike may 

 become similarly changed, while at the same time the 

 internodes of the axis become suppressed and the 

 flowers remain undeveloped ; this gives rise to the 

 " rose-plantain " (PL XII, fig. 3). This is obviously 

 an example of correlation of growth. In many Com- 

 positas, e. g. the daisy (Bellis perennis), the bracts of the 

 involucre may develop as foliage-leaves ; the same is 

 also true of many Umbelliferae, e. g. Daucus Garota. 



Schmitz observed in abnormal inflorescences of the 

 cypress spurge (Euphorbia Cyparissias) that the in- 

 volucre was no longer represented by a whorl of five 

 small bracts alternating with crescent- shaped glands, 

 but had become resolved into spirally- arranged small 

 foliage-leaves, each bearing a gland on either margin 

 such as is borne not uncommonly by the normal 

 foliage-leaves of Euphorbiaceas. 



Velenovsky describes virescent catkins of Salix aurita 

 in which the bracts of the flowers became leafy and 

 were sometimes also furnished with stipules as in the 

 case of the normal foliage-leaf. 



The three small bracts immediately below the flower 

 of Hepatica triloba sometimes develop as foliage-leaves. 



The spathe of the cuckoo-pint (Arum maculatam) has 

 been seen transformed into a stalked foliage-leaf, thus 

 approximating to the normal condition of Spathi- 

 phyllum. The same change has been seen in the 

 sheathing-bracts of the " cob " of Indian corn. 



In the Conifers, concomitant with the other remark- 

 able changes occurring in the cones, to be described 



