Glands of the Plumb agineae . 233 
leaves of Plumbagineae a special study should have missed 
them, while the more widely distributed but smaller glands, 
about to be referred to, were noted. 
The study of the vegetative organs of any member of the 
family is not proceeded with far when one finds, studded 
over the leaves, stem, &c., sunk oval or circular glands with 
characteristically cruciform diametrical partitions (Fig. 5, i). 
According to Maury 1 these glands were discovered by 
Licopoli 2 in 1865. In 1830, however, Braconnot 3 , when 
making analyses* of the mineral substances secreted by the 
Plumbagineae, suggested the existence of special organs of 
secretion, and, in 1856, Mettenius 4 described and figured the 
glands in question. The latter referred to the occurrence 
of these organs in Armeria , Statice , Goniolimon , Limonias- 
trum and Plumbago , taking special notice of their chalk- 
secreting function. He believed them to be composed of four 
cells, although one figure, that of a gland on the under side 
of the leaf of Plumbago europaea (Taf. XXVIII, Fig. 26), 
shows eight cells — a condition to be afterwards spoken of. 
Maury’s memoir (Organisation des Plombaginacees) is a 
valuable contribution to the study of the life-history of the 
order, dealing wfith it in all aspects, — structure, affinity, classi- 
fication and % distribution. He examined very many species, 
and noticed in them all the minute glands referred to above. 
These he terms Organes de Licopoli. 
In 1866 Licopoli thought that these organs were similar to 
the stomata of Marchantia in function, but in 1878 5 he 
changed his opinion of their nature and named them calci- 
ferous glands. In the later paper he makes mention of nine 
species representing Plumbago , Limoniastrum and Statice. It 
must be admitted that his figures illustrative of these are 
J Maury, Ann. Sci. Nat., ser. 7, tome iv, 1886. 
2 Licopoli, Annali dell’ Acad, degli aspirante naturalisti de Napoli, 1866. 
3 Braconnot, An. de Chimie et Phys., tome Ixiii, 1836, p. 373. 
4 Mettenius, Filices Horti Botanici Lipsiensis, 1856, p. 10. 
5 Licopoli, Gli stomi e le glandole delle piante. Atti della R. Academia delle 
Scienze Fisiche e Matimatiche, vol. viii. 1879. 
