EXTRA-FLORAL NECTARIES. 9l 
bitter taste. Dr. "Veturia Bartelletti, who has made a special stady of this sub- 
stance,* states that it is probably a derivate of tannic acid. 
In the genus Calamus the rumination of the seed is not of great taxonomic 
value, because it happens that of two species which, from many points of view, may 
appear very nearly allied, one may have homogeneous, the other ruminated albumen. 
It is not therefore possible to make use of the character of homogeneity or rumi- 
nation of the albumen as a means of dividing Calamus into two principal sections. 
Leaving out of account its rumination, the albumen of the seed of Calamus is 
always horny or bony.. In the descriptions of the albumen it is termed homogene- 
ous not only when it is really so, but often also when the intrusions of the 
integument are very superficial. The rumination of the seed is very apparent in 
C. erectus, C. Flagellum (and its allied species) C. Huegelianus, C. Gamblei, C. gracilis 
C. melanacantkus, C, Diepenhorstii, C. macrosphaerion, etc. 
The embryo of the seed of Calamus is most commonly situated at or near its 
base (Puare 230, fig. 13), but it is lateral and opposite to the chalazal fovea iu 
C. exilis, C. ciliaris and other species of the group. It is also lateral in C. gracilis 
and C. melanacanthus which have, besides, a ruminated albumen, while in C, Kunzea- 
nus it is lateral and the albumen is homogeneous (PrarE 230, fige. 18, 19). 
XIX.—Extra-floral nectaries. 
So far as I know nectarifluous surfaces of any kind have seldom} been observed 
in the flowers, and never hitherto in any of the other organs of Palms. It 
appears to me, however, that certain special swellings or callosities, which frequently 
exist in certain definite positions, in not a few species of Calamus, should possibly 
be considered extra-floral nectaries. 
I have already alluded more than once, in passing, to the existence of these 
supposed nectaries, which are to be met with: Ist, at the insertion of the leaflets 
on the rachis in their upper axil; and, in the hollow formed by the folding 
of the leaflets at their base, just at their insertion in the lower surface; 3rd, at 
the insertion of the spadices and flagella; 4th, in the axil of every branching of 
the spadix and its subdivisions, such as the spikelets and the involucrophora. 
I have never had any opportunity of studying these nectariform surfaces, 
as they may be termed, in a fresh condition; in dry specimens it is difficult to 
investigate their true nature. These surfaces always have the appearance of small 
swellings of a lighter colour than the adjacent tissue and are formed by two lips, 
more or less tumescent, separated by a cleft or rima, which may be supposed to be, 
in some cases, nectarifluous. 
Most Calami are provided with these: structures, which are particularly conspicuous 
in the axils of the leaflets of €. perakensis and C, ramosissimus, and are extremely 
devoloped at the junction of the partial inflorescences with the axis of the. female 
spadix and. in the axil at the insertion of the spikelets in C. paspalanihus. As good. 
examples of the supposed nectariform structures situated in the axils of tho 
involucrophora I may cite C. Gamblei, C. unifarius var. Pentong, €. adspersus, etc. and. 
* Bull. Soe. Bot. Ital. 1904, p. 309. | a 
t Vide Delpino im Nuovo Giorn: Bot. It. II (1870), p. 61.- Gk dicenda 
