95 



first leaves are peltate like those of the adult while the nepioiiic 

 leaves of the seedling are simpler in form. Goebel believes that 

 the origin of the brood-body is from a leaf anlage which explains 

 their appearing alternately with the foliage-leaves, also the de- 

 velopment of a slender vascular strand. It is more difficult to 

 correlate particular parts. At first one is inclined to homologize 

 the blade of the foliage-leaf with the brood-body and the petiole 

 of the foliage-leaf with its stem. However the petiole of the leaf 

 is more strongly developed than the blade, while the stem of the 

 brood-body is less developed. Stipules which appear very early 

 in the formation of the leaf have no homologue in the brood-body. 

 The foliage-leaf is curved so that the apex is directed inwards 

 while the brood-body remains upright. The brood-body de- 

 velops early from the leaf-anlage and its stem must be regarded 

 as a new structure, the function of which is the dissemination of 

 these reproductive bodies. The part homologous with the foliage- 

 leaf is a group of cells which arises on the inner side of the 

 anlage. No axial buds have been observed in the inflorescence 

 of D. pygviaea so it seems reasonable to regard the brood-bodies 

 as new structures which do not arise from axial buds. 



From the above observations it is seen that reproduction by 

 budding occurs in D. rotundifolia, D. intermedia, D. iongifolia, 

 D. hinata, and if the brood-bodies of D. pygmaea be taken as 

 aborted leaves, the reproduction is by budding in that case also. 

 In each species except D. binata the first leaves of the young 

 plant resemble those of the adult. In D. rotundifolia at least, 

 the resulting form is the same whether the young plant arises 

 from a leaf still attached to the plant, a leaf cutting, or a flower- 

 stalk removed from the plant. 



Whether this is regarded as regeneration or not, depends upon 

 the definition of regeneration which is accepted. Morgan (Re- 

 generation, 23. I90i)says, " The word Regeneration has come 

 to mean in general usage not only the replacement of a lost part 

 but also the development of a new, whole organism, or even a 

 part of an organisn, from a piece of an adult, or of an embryo, 

 or an &ggr Goebel (Einleit. i. d. exp. Morph. d. Pflanz. 136. 

 1908) expresses his idea of regeneration as the phenomenon of 



