470 DEGENERATION, 
Although many of the circumstances above men- 
tioned apply to plants whose structure is habitually 
rudimentary, there is no reason why they may not, 
under due restrictions, be applied to plants whose 
organs are only occasionally defective. 
For further remarks on the subject of Abortion, the reader is referred 
to the sections relating to suppression, etc., also to Moquin-Tandon, 
‘El. Terat. Veget.,’ p. 120; C. Morren, “De Vatrophie en général,” in 
‘Bull. Acad. Belg.,’ t. xviii, 1851, part i, p. 275. 
ChE AP a He a ae 
DEGENERATION. 
Watts the terms atrophy and abortion apply in the 
main to a mere diminution of size, as contrasted with 
the ordinary standard, degeneration may be under- 
stood to apply to those cases in which not only is the 
absolute bulk diminished, but the whole form is altered 
and depauperated. Degeneration, thus, is the result 
not so much of a deficiency in growth as of a perver- 
sion of development. 
Under natural, 7. e. habitual circumstances, the for- 
mation of pappus in place of a leafy calyx may be 
considered as an illustration of degeneration. It is 
evident, however, that no very decided line of demarca- 
tion can be drawn between cases of perversion and of 
arrest of development. 
Formation of scales—These may be mere epidermal ex- 
crescences, or they may be the abortive rudiments of 
leaves. Of this latter nature are the ‘‘ cataphyllary”’ 
leaves which invest the root stocks of so many perennial 
plants, the perule of leaf-buds, or the pales on the 
common receptacle of composite flowers. Other illus- 
trations of a like character are to be met with in the 
