20 INTRODUCTORY ESSAY. 
.. The mo e distinctly flagelliform the spadices are, the more elongated is the 
portion of their axis interposed between two partial inflorescences, and in this case the 
base of the spathe is so gradually connected with the axis as to render it impos- 
sible to determine from the outside where the spathe begins to be an organ inde- 
pendent of the axis. When the segments of the axis interposed between two 
partial inflorescences are very long these are always, at least in their lower parts 
armed externally, like a flagellum, with simple ternate or even half-whorled claws. 
As a general rule the spathes are more densely armed with — prickles 
on the outer or dorsal than on the inner or ventral side. 
The lowest or outermost primary spathe is almost always somewhat differently 
shaped from those that succeed it, and provides important diagnostic characters. It is 
usually thicker in texture and less cylindric than the others; is not infrequently 
flattened and two edged and is more spinous on the margins and on the back 
than the upper spathes. In the very earliest stages of the spadix the first spathe 
includes all the subsequent ones; these emerge one from the other like the 
tubes of a telescope. ! 
The upper primary  spathes become gradually shorter and narrower, and the 
ultimate ones help to form the slender filamentous flagellum. 
XIII.-The Partial Inflorescences. 
From or near the mouth of every primary spathe, except the outermost, springs, 
usually distichously, a partial inflorescence. The number of the inflorescences varies 
both according to the species and to the strength of the individual plant. 
In several species the partial inflorescences end in a spikelet larger than the 
lower ones; in others, laterally to the uppermost spikelet springs a more or less 
distinct caudicle formed of diminutive sheathing spathes and representing the prolong- 
ation of the axis. 
The lower inflorescences of a spadix are almost always larger and more branch- 
ed, and bear more spikelets than the upper ones; there is a gradual diminution 
in size, degree of branching and number of spikelets of the inflorescences from the 
base of the spadix towards the apex, where the partial inflorescence is not infre- 
quently reduced to a few spikelets or even to a single spikelet, 
"The spathes which sheath the axis of the partial inflorescences follow the same 
rule as the primary spathes, from which indeed they do not essentially differ, 
and become gradually shorter and narrower as they approach the apex. 
XIV.—The Spikelets. 
The ultimate divisions of the partial inflorescences bear small axes beset with 
flowers which may be considered spikelets, which name I find preferable to that of 
* Juli” employed by Martius. The name “Julus” or ‘‘ Amentum ” (Catkin) is usually 
applied to a cylindric inflorescence where the flowers are attached all round a central 
axis, whereas in the spikelets of Calamus the flowers are almost always regularly 
arranged in two series right and left of the central axis so that the spikelets appest 
flattened exactly as in many Graminee, 
