Fan. 13, 1870] 
Entomological Society of London, January 3.—Mr. H. 
W. Bates, president, in the chair. The fifth part of the ‘‘ Trans- 
actions for 1869” was on the table. A splendid collection of 
butterflies was sent for exhibition by Mr. Hewitson ; it included 
135 new species, and many other rarities, the whole having been 
captured by Mr. Buckley in South America. Observations thereon 
were made by Mr. Buckley, the President, Mr. Higgins, and 
Mr. Wallace.—Professor Westwood, Mr. Bond, Mr, Pascoe, 
Mr. Albert Miiller, and Mr. Quaritch, also exhibited various 
objects, and made remarks thereon.—Papers were read on Zphe- 
meride, by the Rey. A. E. Eaton; on Cadlidryas, by Mr. A. G. 
3utler ; on Catasareus, by Mr. F. P. Pascoe; and on the genera 
of Coleoptera, studied chronologically (Part I., from 1735 to 1801), 
by Mr. G. R. Crotch. 
Royal Horticultural Society, December 21, 1869.— 
Scientific Committee.—Mr. W. W. Saunders in the chair. ‘The 
secretary, Rey. M. J. Berkeley, exhibited a leaf of Aerides ‘“ Fox- 
brush” with a peculiar form of spot, differing from any he had 
previously seen.—Mr. Laxton sent specimens of peas of the most 
varied character, the result of a single cross.—A very interesting 
paper “On the Fertilisation of Grasses,” from Dr. R. Spruce, 
from which the following are extracts, was communicated through 
Dr. Masters. The paper had reference to the statement of M. 
Bidard that grasses are usually self-fertilised while in the bud : 
it will be published 77 ex¢evso in the Journal of the Society :— 
“Tn gently-flowing rivers of tropical America grow many fine 
aquatic grasses, species of Zuztola, Oryza, Leersia, &c. The 
following note is from my journal, under date December 1849, 
when threading in my canoe among the islands of the Trom- 
betas :—‘ This channel was lined on both sides by a beautiful 
grass—a species of Zzzio/a—growing in deep water, and stand- 
ing out of it two or three feet. The large male flowers, of the 
most delicate pink, streaked with deep purple, and with six 
long yellow stamens hanging out of them, were disposed in a 
lax terminal panicle; while the slender green female flowers 
grew on the bristle-like branches of much smaller panicles 
springing from the inflated sheaths of the leaves that clothed 
the stem. As the Indians disturbed the grassy fringe with the 
movement of their paddles, the pollen fell from the anthers in 
showers,’ and would, doubtless, some of it, attain the female 
flowers disposed for its reception. A parallel case to the above 
is that of the common maize (Zea Mays, L.), where the male 
flowers are borne in a long terminal raceme or panicle, and the 
female flowers are densely packed on spikes springing from the 
leaf-axels.. Here the male flowers must plainly expand before 
the polien contained in their anthers can be shed on the female 
organs below, whether of the same or of a different plant. That 
there are frequent cross-marriages in maize is evidenced by the nu- 
merous varieties in cultivation in countries where it isa staple article 
of food, as in the Andes of Ecuador, where nine kinds, varying 
in the colour of the grain (through white, yellow, and brown, to 
black), in its size, consistence, and flavour, are commonly culti- 
vated ; besides many others less generally known. In Phavrus 
scaber (H. B. KX.) another tall broad-leaved grass, the spikelets 
stand by twos on the spike—a sessile female spikelet, and a 
stalked male spikelet. In the same forest grasses of the genus 
Olyra, whereof some species, suchas O. mucrantha (H. B. K.), 
rise to 10 feet high, and have lanceolate leaves above 3 inches 
broad, and a large terminal panicle, with capillary branches, like 
those of our Avia caspatosa: it is the lower flowers that are male, 
with large innate (not versatile) anthers, and the upper that are 
female, with two large stigmas, that are either dichotomously 
divided, or clad with branched hairs, thus exposing a wider sur- 
face to the access of the pollen. And as the panicle is often 
pendulous, many of the male flowers, although placed lower 
down the axis, are actually suspended over the terminal female 
flowers. It is generally to be remarked of diclinous grasses, that 
either the male flowers are very numerous, as in Zea Mays, or 
the stamens are multiplied in each male flower, as in Pariana, 
Leersia, Guadua, &c. ; or the stigmatic apparatus of the female 
flowers is enlarged, so as almost to insure impregnation, as in 
Olyre and Tripsacum. In the Bambusce 1 have gathered 
belonging to the genera Guadua, Merostachys, and Chusquea, 
the flowers are more or less polygamous, and the stamens of the 
male flowers often doubled. But there is scarcely a genus in the 
whole order which is not described as having some flowers by 
abortion, neuter or male, and especially those that have biflorous 
spikelets, such as the Famicez. Some grasses, of normally her- 
maphrodite genera, are not unfrequently truly unisexual, such as 
certain species of Andvofogon, I have occasionally seen panicles 
NATURE 
295 
of Orthocladus rariflorus (Nees), a grass peculiar to the Amazon, 
quite destitute of stamens, and therefore purely female. To come 
home to our own country: is all the pollen wasted that a touch 
or a breath sets free from the flowers of grasses in such abun- 
dance? Watcha field of wheat in bloom, the heads swayed by 
the wind, lovingly kissing each other, and doubtless stealing 
and giving pollen. Consider, too, that throughout Nature, 
heat or moisture, or both, are essential to the emanation of 
the impregnating influence. In all our Festucee, as well as in 
Cynodon, Leersia, and some other genera, the stigmas are pro- 
truded from the side or from the base of the flower at an early 
stage, often before the stamens of the same flower are mature— 
thus as it were inviting cross-fertilisation from the more precocious 
stamens of other plants which are already shedding their pollen. 
All who have gathered grasses will have remarked that some have 
yellow anthers, others pink or violet anthers ; and that anthers of 
both types of colours may co-exist on distinct individuals of the 
same species. The same peculiarity is just as noticeable in 
tropical grasses, and (without professing to give a complete 
physiological explanation of it) this is what I have observed 
respecting it. The walls of the anther-cells are usually of some 
shade of purple, but are so very thin and pellucid, that when 
distended with mature pollen the yellow colour of the latter is 
alone visible. When the pollen is discharged, the anthers re- 
sume their original purple colour, shortly, however, to take on 
the pallor or dinginess of decay. Where the anthers emerge of 
a purple hue, and change from that to brown, it will probably be 
found that they have discharged their pollen while still included 
in the flower. These observations, made without any reference 
to the question now in hand, require to be renewed and tested ; 
and in them, as in all that precedes, I am open to correction. Of 
grasses with bisexual flowers, there are two ways in which the 
ovary may be fertilised, viz., either by the pollen of its own 
flower (closed or open), or by that of other flowers, after the 
manner of the diclinous species. In the latter case, the pollen 
may be transported by the wind, or in the fur of animals (as I 
have observed the seeds of Se/aginel/as in South America), or in 
the plumage of birds. The agency of insects has not been 
traced in the fertilisation of grasses, but may exist. The littlé 
flies I have seen on the flowers of grasses seemed bent on de- 
positing their eggs in the nascent ovaries, but may also have 
aided in cross-fertilisation, In the Amazon Valley grasses are 
often infested by ants, who, indeed, leave nothing organic un- 
visited throughout that vast region ; and they also, I think, can- 
not help occasionally transferring grains of pollen from one flower 
to another. The flowers of palms and grasses agree in being 
usually small and obscurely coloured, but contrast greatly in the 
former being in many cases exquisitely and strongly scented, 
whereas in the latter they are usually quite scentless. The odour 
of palm-flowers often resembles that of mignonette ; but I think 
a whole acre of that ‘darling’ weed would not emit more per- 
fume than a single plant of the fan palm of the Rio Negro 
(Mauritia Carara, Wallace). In approaching one of these 
plants through the thick forest, the sense of hearing would 
perhaps give the first notice of its proximity, from the merry 
hum of winged insects which its scented flowers had drawn 
together, to feast on the honey, and to transport the pollen of 
the male to the female plants ; for it is chiefly dicecious species 
of palms that have such sweet flowers. The absence of odori- 
ferous flowers from the grasses seems to show that insect aid is 
not needed for effecting their fecundation, but does not render its 
accidental concurrence a whit less unlikely. That grasses, not- 
withstanding their almost mathematical character, vary much as 
other plants do, is plain from the multitude of osculating forms (in 
such genera as Lvagrostis, Panicum, and Paspalum), which 
puzzle the botanist to decide when to combine and when to sepa- 
rate, in order to obtain what are called ‘ good species.’ Hence 
the conclusion is unavoidable that in grasses, as in other plants, 
variations of surrounding conditions induce corresponding modi- 
fications of structure, and that amongst the former must be 
enumerated cross marriages, however brought about. If the 
flowers of grasses be sometimes fertilised in the bud, it is pro- 
bably exceptional, like the similar cases recorded of orchids and 
many other families. To conclude: the more I ponder over 
existing evidence, the more I feel convinced that in its perfect 
state every being has the sexes practically separated, and that 
natural selection is ever tending to make this separation more 
complete and permanent; so that the hypothesis of Plato, that 
the prototype even of man was hermaphrodite, may one day be 
proved to bea fact !” 
