ABORTION. 467 
or imperfect development of the indusium, as in what 
are termed exindusiate varieties.’ 
General remarks on abortion, coincident changes, &c—Refer- 
ence has already been made, while treating of hyper- 
trophy, suppression, &c., to certain other changes 
affecting the flower at the same time. Atrophy of one 
organ or set of organs, for instance, is frequently 
accompanied by a compensating hypertrophy or by an 
increased number of other parts. In the feather-hya- 
cinth, Muscari comosum, var., monstroswm, the absence 
of flowers is compensated for by the inordinate for- 
mation of brightly coloured threads which appear to 
be modified pedicels (see pp. 347, 348); so also in the 
wig plant, Rhus Cotinus. So the atrophy of the sta- 
mens, in some flowers, is coincident with the hyper- 
trophy of the pistil. Thus, Unger, ‘ Denkschr. d. Kais. 
- Acad. der Wissensch. Math. Nat. Classe,’ Mai 25, 1848, 
p- 103, tab. ix, describes a case wherein the corolla and 
stamens of Desmodium marylandicum were atrophied, 
while the calyx and legume, on the other hand, were 
hypertrophied. 
Fusion of the members of one whorl with one 
another, or with the components of an adjacent series, 
often entails atrophy or suppression, either in the 
united organs themselves, or in adjacent ones. A 
fohaceous condition of the outer portions of a flower 
is very generally attended by atrophy or complete 
suppression of the inner portions. 
From this point of view the observations of Morren’® 
on the different degrees of atrophy up to complete sup- 
pression, observable in the flowers of Bellevalia comosa, 
are of importance. According to this observer, the 
most highly differentiated parts, such as the stigmas, 
the ovules, and the anthers, are the first to disappear, 
1 See Moore, ‘ Nature-Printed Ferns,’ 8vo, for numerous illustrations 
both of depauperate and exindusiate ferns. Scolopendrium vulgare 
seems to be one of the ferns most commonly affected im this way. 
Moore, loc. cit., vol. ii, pp. 135, 147, 159, 165, &e. 
2 Bull. Acad. Belg.,’ t. xvii, p. 38, t. 1; Lobelia, p. 85. 
