ZESTIVATION AND ITS TERMINOLOGY! 
THE term estivation, to denote the arrangement of the 
parts of the calyx, corolla, etc., in the bud, as well as that of 
vernation for leaves in a leaf-bud, was introduced by Linnzus. 
He did not elaborate the former subject as he did the latter, 
and the few terms given to the modes he recognized are for 
the most part defined merely by a reference to their use in 
vernation. Aistivation as a botanical character is compara- 
tively recent, and its terminology is not yet quite satisfactorily 
settled. I propose to consider, (1) what the leading modes 
are, and (2) how they are to be designated. 
(1) In the first place, the modes of estivation may be con- 
veniently divided into two classes, those in which the parts 
overlap, and those in which they do not. 
Of overlapping zstivation, only two principal kinds need 
be primarily distinguished, namely: 1. where some pieces 
overlap and others are overlapped, 7. e., some have both 
margins exterior and others both margins interior or coy- 
ered; 2. where each piece of a circle is overlapped by its 
neighbor on one side while it overlaps its neighbor on the 
other. There are mixtures and subordinate modifications of 
these two, but no third mode. 
In estivation without overlapping, there is, first, the rare 
case in which the parts of the whorl or cycle never come into 
contact in the bud; and, secondly, that in which they impinge 
by their edges only. There is also the case in which both 
margins of each piece are rolled or bent inward, and the rarer 
one in which they are turned outward ; and the apex of each 
piece may comport itself in any of these ways. But these 
dispositions are those of the pieces or leaves taken separately, 
and the terms applied to them are the same as in vernation or 
1 American Journal of Science and Arts, 3 ser., x. 339. (1875.) 
