872 THE AMERICAN NATURALIST. [Vor. XXXVI. 
in nepionic development, but in the reverse order of succession. 
He has shown this at length in his “ Genesis of the Arietidae," 
published in part as a paper of the Museum of Comparative 
Zoólogy of Cambridge, and as No. 673 of the .Swthsontan 
Contributions. It is given more simply and concisely in a 
paper, * Cycle in the Life of the Individual (Ontogeny) and in 
the Evolution of its Own Group (Phylogeny)," Proceedings of 
the American Academy of Arts and Sciences, Vol. XXXII, 
No. 10, as well as in other papers. This case seems to be 
comparable in that it is a failure to develop the full characters 
of an earlier adult condition, due to the strength of the plant 
going into the production of flower and seed instead of develop- 
ing leaves. The tip of the leaf in all cases repeats the triden- 
tate character of the first nepionic leaf, both in the tip of the 
leaf proper and in the tips of all the divisions. 
Viola tricolor L. (Pansy). 
This plant is very seldom a perennial, but often comes up 
from the rootstock the second year. Such plants are easily 
obtained, and so exactly do the stages compare with the seed- 
ling that were it not for the rootstock and the absence of 
cotyledons the two might be easily mixed. The seedling is 
figured by Lubbock, Seedlings (1892), and in that and in 
seedlings examined the stages were exceedingly like those of 
the early spring growth from a rootstock. The reversal of these 
stages beneath the flower is seen with varying definiteness. 
The old single form known as heart's-ease seems to show this 
best. The number of notches decreases and the leaves return 
to the forms seen in the beginning, those directly beneath the 
flower being exactly like the first of the spring growth of the 
adult and the first nepionic (Pl. III, Figs. 1 and 2). 
Rosa rubiginosa L. (Sweet Brier). 
In this plant, perhaps, of those given here, the stages are most 
easily and completely seen. The seedling varies, having the first 
nepionic leaf single as in Pl. IV, Fig. 1, or it may be trifoliolate 
like the second leaf of Fig. r, as in Fig. 2; in each case the 
