62 
TUB GARDENING WORLD 
January ; >i , 1903. 
* Gleanings from the World of Science. * 
The undermentioned subjects were discussed at the meeting of 
the Scientific Committee of the Royal Horticultural Society on 
the 13th inst. :—• 
Mezebeon Dying. —-Mr. Holmes showed specimens, and re¬ 
marked upon the suddenness with which they died off- Dr. Cooke 
undertook to examine and report upon them. 
Ranunculus abyexsis. —He also referred to this plant, as said 
by Sowerby to be poisonous, to sheep. Though the genus is gene¬ 
rally more or less poisonous, this species does not appear to have 
been specially noticed by other writers. 
Cedbus Deodaba. —Mr. Bowles exhibited a male catkin of this 
tree, which had become proliferous, bearing several branches, all 
being staminiferous. 
Pintjs Bungeaxa, Babk. —Dr. Masters showed a specimen or 
the bark of this tree from China, which was silvery white and 
scaling off. Though cultivated in England, it had not as yet pro¬ 
duced a white bark. He mentioned that Abies arizonica had a 
similar bark, both resembling that of the common Birch 
Maize and bogy nous. —Dr. Masters also showed specimens, 
received from Mr. F. M. Bailey, of Brisbane, Queensland, of 
which the following were typical examples:—(1) This had, one 
small cob of grains arising from the base of nine male spikes ; 
single female flowers were scattered at intervals on the latter, 
both near the bases and summits. (2) Fifteen male spikes had 
one terminated with a small cob; isolated female flowers were 
scattered throughout among the male flowers. (3) This had 
about twelve male spikes, all being female below and terminated 
by male flowers above ; the whole formed a dense mass of small 
cobs,, giving the appearance of a proliferous cob with male flowers 
above. 
Practical Pollination. —Mr. Davidson, of Fanners, Wickham 
Bishops, Essex, described an ingenious method of artificial fer¬ 
tilisation of flowers, as follows:—“I have adopted a method of 
economising pollen, the ordinary cameTs-hair brush being very 
wasteful. If a stick of sealing-wax be rubbed briskly on the coat 
sleeve as for electrical experiment, and then presented to the 
flower, the pollen flies to it and adheres. Every particle can thus 
be utilised far more easily than with a brush.” 
Climbing Plants.— Mr. Davidson also forwarded the observa¬ 
tions he had made on Hoyas, etc. :—“ I have had a number of 
Hova carnosa plants under observation for a considerable time, 
and. though they twist resolutely enough in one direction during 
the day, the hours of darkness usually appear to have been a 
period of indecision, t he work of the day being sometimes more or 
less undone during the night. While they are decided enough in 
twisting their way up living plants, they show no such decision 
in climbing up dead supports. For instance, if I slightly untwist 
a Hoy a from a growing plant, it coils round again in a very short 
time, whereas if a stick is substituted for a plant the Hoya almost 
never regains its old position without assistance.” It was thought 
by the committee that this difference was more elite to the smooth 
or rough nature of the surface than the fact of the support being 
either alive or dead. 
Yucca bectjbva.— Mr. Worsley sent some leaves, upon which 
Dr. Cooke reported as follows : —“ The leaves of the Yucca recurva 
exhibit long dark streaks, which I have observed before, but could 
never attrioute to any specific form of fungus. Ini the present 
instance I have failed to discover any liyphse or spores, but pro¬ 
bably if watched there might be some future development. At 
present there is no evidence of fungus parasitism, and I do not 
remember that any has been recorded as affecting the leaves of 
Yucca.” 
Loganbebby Roots. —Mr. F. Sharpe, of Westbury, Wilts, sent 
some roots bearing nodules, upon which Dr. Cooke reports as 
follows :—“ The nodules on roots of this plant resemble most of 
the root nodules which I have examined in giving no definite clue 
to any parasitism. There is no evidence of the presence of 
bacteria as far as I can detect (350 diamsj ; and nothing has re¬ 
sulted from preserving them for twelve days in a damp 
atmosphere.” 
Celebiao. —Dr. Cooke reports as follows upon the specimens 
sent to the last meeting:—“Roots marked with discoloured 
blotches or stains internally, and sometimes in circles or seg¬ 
ments, at a short distance from the periphery. The discoloured 
tissue did not exhibit any trace of hyphse or anything further 
than the discolouration of the cell contents. I can see no in¬ 
dication or suspicion of fungus parasitism.” The thanks of the 
committee were given to Dr. Cooke for his report. 
Peas Attacked by Grams.—Mr. Baker brought a samifle of. 
wrinkled Peas badly attacked by grubs, upon which Mr. Sutton 
has reported as follows : —“ There is nothing whatever in the 
condition of the Peas to indicate any injury beyond that pro¬ 
duced by the maggot which is common in Green Peas. It is 
always the case in shelling culinary Peas that a certain propor¬ 
tion are maggoty. The condition of the sample is entirely due, 
in my opinion, to the fact that the wet and cold summer greatly 
increased the proportion of maggoty seeds. Not one of the seeds 
appears to be attacked by the Pea weevil, and wrinkled Peas 
grown in England are very seldom weevilled. The only sorts of 
English growth usually attacked are the early round seeded 
kinds, and then only in hot, dry summers, and when grown on 
light dry soil. I doubt whether any sample of English Pea« 
of last year’s harvest was at all seriously attacked by the weevil 
owing to the absence of sun and heat.” 
Statistical Yaeiations. —Mr. Henslow drew attention to a 
paper in the Botanical Gazette, vol. xxxiii., p. 462, on “ The 
Numerical Relation of the Ray Flowers of Composite,” by Mr. 
E. Mead Wilcox, in illustration of the mathematical and statis¬ 
tical study of variation, as throwing light upon the origin of 
species. The author quotes the following remarks of Dr. Daven¬ 
port : “ The science of variation is one of those that we may hope 
to see established in this century. I feel convinced that statis¬ 
tical studies are first of all necessary to lay the foundations of 
science.” Mr. Henslow expressed his disbelief in any advan¬ 
tage accruing from this method, because such statistics are only 
based on “ individual variations ” which do not give rise to 
variations of which systematists can take any account, i.c., as 
long as the plants are living under the same conditions of life. 
They are merely fluctuating details due to the qualities of 
growth, of which Dr. Wallace observed :—■“ They are due to the 
laws which determine the growth and development of the 
organism ; and, therefore, rarely coincide exactly with the limits 
of a species.”—( Foit nightly lie view, March, 1895, p. 444.) The 
author referred to “ treats of the numerical variation found in 
the ray florets of Helianthus animus.” He examined 1,103 
heads, and counted the number of ray florets. His conclusion 
is as follows : “ The class having 21 ray flowers included over 
31 per cent, of all the individuals ; slightly over 10 per cent, ot 
all the individuals are segregated in classes, 30 to 34 inclusive ; 
while only three individuals were found having more than 34 
ray flowers.” He ought to have noticed and added a third group 
containing about 13 florets, represented in the curve given. He 
adds: “ The curve shows a positive skewness of 1-1, but at 
present it cannot be Stated whether this skewness is toward or 
away from the ancestral conditions of the species.” The curve 
exhibited shows an enormously high maximum at 21, and two 
small ones about 13 and 34, 30 times less in height. Now, if 
the author had simply observed the phyllolactical arrangement 
of the florets in the head, which represents a depressed cone, 
he would have, I think, without doubt, found that it was to 
be represented by the “ angular divergence ” of 8-21ths, for the 
maximum of 21 flowers signifies this, while the two numbers, 
13 and 34, represent the fractions 8-l3ths and 13-34ths, one on 
either side of the maximum, 8-21ths. When cones and “heads” 
of Composite, etc., are phyllotactically examined, iib will almost 
always be found that certain suppressions occur ; a leading or 
“ generating ” spiral may be selected, but in consequence of in¬ 
equalities of growth, other subsidiary spirals interfere. 
Similarly in the Helianthus the fluctuations around the numbers 
13, 21, 34, mean that certain florets are suppressed, while the 
•other maxima than 21 indicate the secondary spirals. The 
“ skewness ” to which Mr. Wilcox refers is a necessary result 
with angular divergencies higher than fths, because 360 is not 
divisible by 13, 21, or 34 without remainders. Hence, none of 
the spirals represented by these can have the initial numbers 
of the “cycles” in a vertical line on cones, nor on a radius 
in heads. The author makes no allusion to phyllotaxis, so is 
apparently unaware that it completely explains his curves with¬ 
out. appealing to any ancestral origin of the maxima. 
DELAYS in the post may he avoided if you will, 
at once, alter the address of THE GARDENING 
WORLD in your books to 37 and 38, Shoe Lane, 
London, E.C. 
