solution, then determinations of the glucose must be made
in portions of each of the filtrates.
In this case determine
(1) The original 'reducing power' of the maltose
solution.
(2) The 'reducing power' of the same after the
action of the maize.
(The increase of ' reducing power ' will be due partly
to the formation of glucose by hydrolysis of maltose and
partly to sugars formed from the maize itself.)
(3) The reducing power of the solution obtained in
the control experiment.
The amount of glucose in the filtrate from the actual
experiment can be calculated from the difference between
the values obtained for the ' reducing power ' in (2) and
(1) by the method explained on p. 285 ; and if the amount
of glucose found in (3) be subtracted from this the result
gives the amount of glucose formed from maltose in the
experiment.
The determinations of ' reducing power ' may be made
CH. XVl] SYNAPTASE. 311
voliimetrically with Fehling's solution, but it is not neces-
sary to remove the dextrins present in these experiments,
as rough results are sufficient to give the chemical evidence
in a perfectly conclusive form.
Decomposition of a glucoside (salicin) by a
ferment (synaptase) from another plant.
Add to a 5 p.c. solution of salicin (which gives no
reaction with dilute ferric chloride), some paste of bitter
almonds ground up with water and sand. Digest for a few
hours on the water bath at 40° — 50°C., filter clear and test
a portion of the filtrate with dilute ferric chloride, a deep
purple colour is produced (destroyed by acids or alkalies)
due to saligenol, formed by hydrolysis of salicin.
CiaH^sO; + H,0 = CeH, . OH . CH, . OH + CeH^.O^.
Salicin Saligenol Glucose.
CHAPTER XYII.
GENERAL EXPERIMENTS.
General Experiments.
(1) Determine the increase per day of nitrogenous
compounds and cellulose in vigorously growing Spirogyi'a.
Take some healthy Spirogyra which has been well
washed in distilled water, filter and allow it to drain on a
perforated filter plate. Weigh out two equal portions
(about 15 — 20 grs. each). Place one portion (B) in
ordinary water and expose it to bright sunlight. Dry the
other portion (A) at 30°, and note its dry weight.
Extract one portion of A with 2 p.c. soda and deter-
mine the proteids in the extract (nitrogen by Wanklyn's
albuminoid ammonia process, see p. 255).
Extract another portion of (^) with dilute alcohol and
then with 1 p.c. sulphuric acid and treat the residue
with ammonia and bromine water (see p. 293) : then dry
the residue at 100° C. and weigh ( = cellulose).
At the end of twenty-four hours take out the whole of
B and wash thoroughly with distilled water ; then collect,
dry, and treat in same way as A. The increase of proteids
CH. XVIl] EXPERIMENTS. 313
and cellulose in B will be the amounts formed per day by
the weight of Spirogyra taken.
(2) Shew that formation of starch is influenced by
supply of inorganic salts.
Take some young leaves of Sparganium naUvns (or
shoots of Elodea canadensis) and grow one portion {A)
in pure distilled water, and another portion {B) in a
culture solution, both being freely exposed to light and
air, for several days.
Determine in portions of A the p.c. of starch (if any)
and the p.c. of (sulphated) ash.
Do. in portions of B.
(3) Trace the changes which occur during germina-
tion in the reserve materials of an oily seed under
different conditions.
Take three equal weights (about 10 grs. each) of air-
dried hemp-seeds {A), (B), (C).
Allow B and C to germinate on damp asbestos cloth and
when the plumules have reached a length of 2 — 3 cm.,
place B in a bell-jar arranged so as to exclude CO 2^ : place
C under similar conditions, but with free access to COo :
leave B and C exposed as much as possible to light for
about a fortnight. Then kill them by chloroform vapour
and dry at 25°— 30°.
Note weights (air-dried) of ^ , B, and C.
Make extracts of aliquot portions of A, B, and G, and
determine for each of them, (1) nitrogenous compounds,
(2) oils and fats, (3) sugars, (4) starch, (5) cellulose.
1 See Part I., Fig. 8, p. 30.
APPENDIX I.
Many of the above experiments give very varying results
with different material. As instances of extreme variations
we may mention two of our experiences.
On one occasion the shoots of Oiwhrychis sativa which
had been kept for the usual time in the dark contained
scarcely a trace of amides, and on another no traces of tartaric
acid could be detected in beet-root juice, which commonly
contains enough of this acid to be easily detected without an)'-
special skill in this kind of analysis.
We have therefore added the following notes on our
experiences in conducting these experiments with students,
and given the numbers obtained for the quantitative results of
fairly representative cases.
We have tried as far as possible to arrange the quantita-
tive experiments so that fairly accurate work will clearly
demonstrate the principles involved, but in such cases as the
estimation of proteids and mixed sugars very careful work is
essential.
Chapter X. p. 259. Froteids, etc.
Qualitative.
The NaOH extract will contain large quantities of proteids
insoluble in water and give a copious precipitate when
neutralised.
APP. l]
RESULTS.
315
The aqueous extract always contains some proteids soluble
in water and may contain a small amount of peptones and
albumoses, but these substances are often absent, or present
only in traces.
Considerable quantities of amides will be found. Traces
of ammonia, nitrates, and nitrites sometimes occur, but com-
monly these compounds are absent.
Quantitative.
The following values were obtained in a set of experiments
with seeds and shoots of Onohrychis.
The p.c. are calculated for air-dried material in each case.
Proteids insoluble in water
Proteids soluble „ „
Peptones and Albumoses
Amides
Ammonia
Nitrates and Nitrites
'itesj
Seeds.
Shoots
normal.
Shoots
kept m
the (lark,
64-3
17-8
8-0 p.c.
2-8
41
4-2 p.c.
nil
0-7
0-5 p.c.
trace
0-5
5-9 p.c.
nil
nil
nil p.c.
Ammonia. Nitrates, etc. (p. 260).
Experiment No. 1
Normal shoots.
Shoots kept in
the dark and
absence of
oxygen.
Shoots from plants
watered with
ammonium
nitrate.
Ammonia
trace
2-8
1-3 p.c.
Nitrates
nil
nil
1-7 p.c.
Nitrites
nil
nil
0-8 p.c.
Chapter XI. p. 265. Oils ayid Fats.
Qualitative.
If a portion of the oil from Lepidium seeds is qualitatively
examined it will be found that the whole of the oil is not
316 EESULTS. [APP. I
saponifiable by aqueous or alcoholic potash. The exact chemical
nature of the unsaponifiable substances is uncertain, but they
are probably not plastic.
Considerable quantities of glycerin can be detected after
saponification of the oil.
Quantitative.
Values obtained with seeds and seedlings of Lejndium.
The p.c. are calculated for material dried at 100° C.
Experiment ^o.
1
3
2
Seeds,
Seeds, germi-
nating radicle
protruding a
few mm.
Seedlings and
remains of seed,
Oils and Fats
30-2
23-7
5-2 p.c.
Glycerin produced
by saponifying oil from
100 grs. of material
dried at 100°.
3-1
grs.
1-8 grs.
0-5 grs.
Chapter XII. p.
275.
Tannins and Glucosides.
Qualitative.
Experiment No. 1. Willow Bark.
Much tannin is generally present, which is best removed
by hide powder ; but shaking with lead carbonate will also
remove the tannin completely if the process is repeated several
times.
Salicin is commonly present in sufficient quantity to be
easily detected ; and small quantities of glucose are generally
found.
Experiment No. 2.
Young and ripe fruits of Musa. Much tannin and little
sugars may be expected in the young fruits, but in the old
fruits much sugars as well as tannins.
APR l] RESULTS. 317
Chapter XIII. p. 288.
Qualitative.
Experiment No. 1.
Glucoses, cane-sugar, and maltose are generally all present.
Experiment No. 2.
(a) Very little or no cane-sugar or reducing sugars will
be found.
(b) Abundance of glucoses and cane-sugar will be found,
but little or no maltose. Crystals of cane-sugar can easily be
obtained by the strontia method.
Quantitative.
Values obtained in a set of experiments w^ith leaves and
roots of Beta vulgaris.
The p.c. are calculated for material dried at 100° C.
Experiment No. 1.
Total sugars. Leaves. Roots.
Est. by fermentation process and
calculated as glucoses 0*2 6-8 p.c.
Experiment No. 2. (a) (b)
Glucoses 0-5 1-8
Cane-sugar nil nil
Maltose 0-3 0-7
Chapter XIV. p. 293.
Qicantitative.
Values obtained using tubers of potato, leaves of Acer
pseudoplaia'fius, and grains and seedlings of wheat.
The p.c. are calculated for material dried at 100° C. in each
case.
Experiment No. I. (a) (b) (c)
Starch 57-2 56-9 570 p.c.
318 RESULTS. [aPP. I
The results of these three experiments should not differ by
more than 1 — 2p.c.
Experiment No. II.
Values obtained in three different sets of experiments.
Leaves killed in the Leaves killed in the
evening. early morning.
Starch 3-4 2-5 p.c.
4-8 1-7 p.c.
4-0 3-2 p.c.
As the figures indicate the result of these experiments
varies greatly, and apparently in no regular way, but the
greatest difference may be expected when a warm damp night
has succeeded a clear bright day.
Experiment No. III.
Seedlings kept in dark
Grains. for three days.
Starch 59-6 3*0 p.c.
Chapter XY. p. 301. Organic acids, etc.
Qualitative.
For ascertaining what organic acids are present, free and
combined, beet-root juice may be examined, in which varying
quantities of acetic, glycolic, malic, citric, tartaric, oxalic,
succinic, and aconitic acids are commonly present.
Values for old and young petioles of rhubarb.
Experiment No. 1.
Young
Old
Acidity.
petioles.
petioles.
[Calculated as oxalic acid
0-6
2-2 p.c.
H,CA.]
APP. l] RESULTS. 319
Values for ripe and unripe apples.
Experiment No. 2.
Acidity.
Unripe
apples.
Ripe
apples.
[Calculated as
1-2
0-3 p.c.
H,CA.]
Sugars.
Glucoses
0-8
4-6 p.c.
Cane-sugar
nil
0-9 p.c.
Maltose
nil
nil p.c.
The p.c. in experiments
1 and 2
are
calculated for fresh
tissues.
Using leaves of etiolated
and normal
potato plants values
obtained were
Experiment No. 1 (p. 302).
Nonnal leaves. Etiolated leaves.
Ash (sulphated) 4*7 2*5 p.c.
The p.c. are calculated for leaves dried at 100° C.
Experiment No. 2.
Values for ash from grains and young leaves of wheat.
Ash from young Ash from
leaves. grains.
PA 40 48-5 p.c.
The p.c. are calculated for ash — i.e. represent weights of
P^Og and alkali in 100 grs. of ash of each of the substances not
in 100 grs. of each of the substances compared.
Experiment No. 3.
Values for CaC.j04 in young and old leaves of Semj)er-
vivum.
Young leaves. Old leaves.
Calcium oxalate (CaCA) 1"^ "^'l P-c
The p.c. are calculated for fresh leaves.
320 RESULTS. [APP. I
Chapter XVI. p. 305. Unorganised ferments^ etc.
Diastatic Ferments.
Experiment No. 2.
Using the method described in the text (p. 304) an
extract of 10 grs. of fresh malt acting for one hour at 50° on
soluble starch produced 2 "5 grs. of maltose; whilst a similar
extract of 10 grs. of barley grains acting under exactly the
same conditions produced only traces of maltose.
Experiment No. 3.
An extract of air- dried leaves of barley compared under
exactly similar conditions with the same malt extract as used
in experiment No. 2 produced no maltose.
Experiment No. 4.
Adding to the soluble starch solution the finely divided
tissues themselves and not extracts which had been filtered
clear.
10 grs. air-dried leaf acting Leaves of Leaves of
for one hour at 50°, pro- Pisuni Trifolmm
duced from soluble sativum. pratense.
starch.
Maltose 0-6 grs. 0*2 grs.
Invertase. Glycase. Glucoside fermients.
Experiments No. 1 — 3.
Positive results should be easily obtained in all these
experiments.
In No. 3 — where a control experiment is made — we have
never found the quantity of sugars produced by digesting
10 grs. of coarsely ground maize with 200 c.c. of water, for 5
or 6 hours at 40° — 50°, to exceed 0-2 grs. of 'reducing' sugars.
APP. l] RESULTS. 321
Chapter XVII. p. 312. General experhnents.
Experiment No. 1.
An experiment under very f;xvoural)le conditions gave the
values
A (dry weight of Sjnrogyra used) = 21-5 grs.
B (dry weight of Sjnrogyra obtained
after 24 hours) =24-1 grs.
For twenty-four hours.
Increase in dry weight = 2-6 grs.
Increase of proteids = 'Ssjrs. ] p -,i r .
^ * I for 21-5 grs. of
Increase of cellulose =1-3 grs. j
Experiment No. 2.
Using leaves of Sparyanium natans — sixteen days.
A B
in distilled
water.
in a cultur
solution.
Starch
0-4
6-5 p.c.
Ash
M
4-8 p.c.
The p.c. are calculated for material dried at 100° C.
Experiment No. 3.
Values for a set of experiments with hemp seed.
Weights of three portions of original seed.
A. B. C.
10-0 grs. 10-0 grs. lO'Ogrs.
Weights of A, B and C after experiment.
A. B. C.
10-0 grs. 4*2 grs. 11 -1 grs.
D. A. 21
822
RESULTS.
[APP. I
Analysis of A, B and C after experiment.
A.
B.
0.
seeds.
seedlings 14
days without
access of COa-
normal
seedlings.
Nitrogenous compounds |
(N X 6-3) J
21-2
14-6
284 p.c.
Oils and Fats
37-0
nil
6-2 p.c.
Starch
nil
nil
12-8 p.c.
Cellulose
18-6
63-1
25-5 p.c.
Sugars
nil
traces
traces
The p.c. are calculated in each case for material dried at
30° C.
APPENDIX 11.
Reagents required for experiments on Meta-
bolism.
Solids.
Inorganic.
Citric acid.
Asbestos.
Diphenylamin.
Lead carbonate.
Gelatin.
Magnesia.
Hide powder.
Potassium sulphate (acid).
Maltose.
Soda-lime.
Metaphenylenediamin.
Organic.
Phenylhydrazin.
Aniline acetate.
Phloroglucin.
Brucine.
Salicin.
Cane-sugar.
Starch.
Dextrose.
Thymol.
Org^anic liquids.
Alcohol. Commercial absolute.
,, Methylated spirit.
Amyl alcohol.
Benzene.
Chloroform.
Ether.
Ethyl acetate (acetic ether).
Glycerin.
Petroleum ether (completely volatile below 60^ C).
These liquids must leave no residue on evaporation.
21 2
324 REAGENTS. [APP. II
[Alcohol.
Alcohol of about 98 p.c. can be obtained from good metliy-
lated spirit by distilling two or three times off freshly burnt
lime, it should be allowed to stand over the lime for twenty-
four hours before each distillation.
The methylated spirit now commonly sold is useless for
this purpose but the 'ordinary methylated spirit,' which is
still supplied for manufacturing and scientific work, when
treated with lime can be used for all purposes where alcohol
not stronger than 98 p.c. is required.]
Standard Solutions.
Decinormal Sulphuric acid.
„ Alkali (baryta).
,, Potassium permanganate.
„ Silver nitrate.
Uranium acetate (1 c.c. = -005 grs. P0O5).
Nessler's \ prepared as described
Ammonium chloride linWanklyn's "Water
Alkaline potassium permanganate J Analysis."
Fehling's.
Sachsse's (alkaline mercuric iodide).
Barfoed's (4 grs. cryst. cupric acetate + 1 gr. acetic acid
per 100 c.c.)
Solutions in -water.
Acids.
Hydrochloric '\
Nitric > (concentrated and 10 p.c.)
Sulphuric J
Acetic (glacial and 10 p.c.)
APP. Il] REAGENTS. 325
Oxalic (saturated).
Trichloracetic (10 p.c.)
Alkalis.
Liquor Ammoniae.
Ammonium carbonate (saturated).
Baryta-water \
Lime-water \ (saturated).
Strontia-waterJ
Soda (caustic) (2 p.c, 10 p.c. and 50 p.c.)
Sodium carbonate (saturated).
Copper acetate (10 p.c.)
Copper sulphate (10 p.c.)
Lead acetate (saturated).
Basic lead acetate (prepared by boiling 100 grs. of lead
acetate and 70 grs. lead oxide (litharge) with 500 c.c.
of water for half-an-hour and filtering).
Millon's reagent (mercuric nitrate and nitrous acid).
Potassium ferrocyanide (saturated).
,, ferricyanide (5 p.c.)
„ nitrite (20 p.c.)
Sodium acetate (20 p.c.)
Sodium phosphotungstate (saturated).
Ferric chloride (10 p.c.)
Bromine-water (saturated).
Litmus (neutral).
Solutions in 98 p.c. alcohoL
Mercuric chloride (saturated).
Thymol (saturated).
Phloroglucin (5 p.c.)
Phenolphthalein (3 p.c.)
326 MATERIAL. [APP. II
Special apparatus.
Lunge's Nitrometer.
Soxhlet's Fat-extraction apparatus \
Arrangement for continuous agitation.
Material required.
Seeds of Cress (Lepidium sativum).
„ Sainfoin {07iobrychis sativa).
5, Hemp [Cannabis sativa).
Young and ripe fruits of Apple.
,, Banana (JIusa sajneyitum).
Bark of Willow (Salix vimhialis).
Leaves of Pea {Pisutn sativum).
„ Barley (Hordeum).
„ Clover (Trifolium).
„ Tropseolum.
„ Beetroot or Mangold-wurzel {Beta).
„ Sycamore {Acer pseudoplatanus).
„ (Old and young) of Sempervivum teetotum,.
„ ,, Rhubarb {Rheum).
,, (of normal) Potato.
,, (of etiolated) Potato.
Roots of Beetroot or Mangold-wurzel.
Grains of Barley.
,, Maize.
„ Wheat.
Bitter almonds.
Fresh Malt.
,, Yeast.
„ Spirogyra.
,, Shoots of Elodea canadensis, or Spargayiium nataris.
1 Schleicher and Schiill have recently introduced paper shells for use
•with Soxhlet's apparatus in place of the inner tube, which are very
satisfactory.
INDEX.
Absorption by roots of water and
salt in certain proportions, 73 ;
of water by dead roots, 78 ; by
transpiring plant, 79
Acer negundo, oxalate in, 66 ;
used in experiments on starch,
294
Acer pseudoplatanus, for water
culture, 62
Acid, effect on chlorophyll of, 51 ;
malic, effect of, on antherozoids,
215
Acidity, see Acids
Acids, organic, 295; tests for,
296 ; determination of acidity,
297 ; experiments on, 301, 318
Acton, on assimilation of sugar,
32 n. ; on water-culture, 58 n. ;
on species suitable for water-
culture, 61
Adoxa, runners of, 194
iEsculus hippocastanum, oxalate
in, 66
After-effect, 171 ; heliotropic, 181
Agitation, machine for continuous,
243
Air, passage of, under pressure
through cell-walls, 88
Air-pump, suction of, compared
with transpiration current, 95 ;
Strasburger's and Janse's tran-
spiration experiments with, 96
Albumoses, see Proteids
Alcohol obtained from methylated
spirit, 324 ; use of, in extrac-
tion, 242 ; use of, in pi'ecipita-
tion, 281, 305
Alisma, for water-culture, 162
Alkali, use of, in extraction, 245
Alkalinity, see Acids
Amaranthus, anthocyan in, 52
Amides, qualitative tests for, 252 ;
estmiation of, 257, 258 ; experi-
ments on, 259, 260
Ammonia, 253, 260, 315 ; estima-
tion of, 259
Analysis, preparatory treatment of
material for, 240
Anisotropism, 121, 122
Antherozoids attracted by malic
acid, 214
Anthocyan, 52
Apheliotropism, 182
Apogeotropism, 164
Apparatus for culture of plants
without COo, 28, 30 ; for record-
ing geotropic and sleep move-
ments, 172, 223 ; and manipula-
tion, books dealing with, 240;
Winkler-Hempel, for gas-analy-
sis, 7,
Aquatic plants, see Water plants
Arc-indicator of Sachs, 152
Aristolochia, nitrates in, 66
Arum, stomata of, 107
Arundo donax, variegated leaves
of, tested for starch, 23
Ash of tissues, processes for obtain-
ing, 298 ; constituents of, 299 ;
determination of chlorine — phos-
phoric acid — alkalies — in, 299-
300. See also Salts
Asparagin, see Amides
Aspergillus, culture of, 68
328
INDEX.
Assimilation of carbon, 21 ; affected
by chloroform, 38 ; by excess
of COo , 26 ; by temperature,
37 ; dependent on presence of
CO2, 28, 29, 37 ; effect of in-
tensity of light on, 24; gain in
weight during, 31 ; of land-
plants under water, 26 ; Pfelfer's
method of estimating COg de-
composed in, 41 ; of sugar, 32 ;
in variegated leaves, 23 ; stomata
in relation to, 26; wandering of
products of, 32
Averrhoa, autonomous movements,
225, 231 ; paraheliotropism,
224
Autonomous movements of Aver-
rhoa, 225, 231; of Trifolium,
230
Auxanometers in general, 149
Auxanometer, self-recording, 153 ;
simple form of, 155
Auxanometer-lever, 158
Bacteria, chemotaxis of, 216
Bacterial method of demonstrating
evolution of oxygen, 48
Balance, spring-, used in tran-
spiration experiments, 100
Baranetzky, his recording aux-
anometer, 149 n., 153
Barfoed's solution, 282
Barium in fungus culture, 70
Barley used in experiments on
ash, 302 ; on enzymes, 306
Bary, de, see De Bary
Bateson, Miss A., on changes in
transverse dimensions of pith,
135. See also Darwin, F.
Beetroot as indicator of injurious
temperature, 15 ; see also Beta
Begonia, root-pressure in, 78
Begonia manicata, for osmotic
work, 129
Beilstein, organic chemistry text-
book on, 239
Bellis perennis, effect of continued
darkness on, 233; periodic
movements of, 233 ; effect of
temperature on opening of flow-
ers, 233 ; effect of contrast of
temperature on opening of flow-
ers of, 234
Benzene, use of in extraction, 245
Benzol, action of, on chlorphyll
solution, 50
Berberis, effect of chloroform on
stamens of, 210; irritable sta-
mens of, 209-211
Beta, used in experiments on
sugar, 288
Blackman, on a method of studying
respiration, 5 n. ; on the import-
ance of stomata for respiration,
26 n.
Blocking of vessels by particles
suspended in water, 86, 87
Blood, used to demonstrate evo-
lution of oxygen, 39
Bloom on leaves, effect of on
assimilation, 26 n.; as affecting
transpiration, 111
Bohm on assimilation of sugar,
32 n.
Bokorny on formaldehyde, 34
Bonnier and Mangin on effect of
chloroform on assimilation, 38
Boussingault, his phosphorus me-
thod of demonstrating evolution
of oxygen, 41
Branches, drooping in frost, 178 ;
horizontal growth of, 196
Brown and Morris on Carbohy-
drates etc., 276, 285, 290, 303
Briicke on rigidity of pulvinus of
Oxalis, 206
Bryonia, tendrils, 200
Bunsen, formula used in gas-
analysis, 44
CaBsium in fungus culture, 70
Calcium in fungus culture, 70
Calcium oxalate, physiology of, 66;
estimation of in tissues, 301
Callitriche, stomata of, 110
Caltha palustris, stomata of, 107
Cane-sugar, see Sugars
Carbohydrates, soluble, see Dex-
trins. Sugars; insoluble, see
Starch, Cellulose
Carbolic acid, see Phenol
Carbonic dioxide, effect of on cir-
INDEX.
329
culating protoplasm, 18 ; ex-
cess of on assimilation, 26
Carpinus, horizontal branches of,
196
Carum carvi, roots of, 136
Caspary on frost affecting curva-
ture of branches, 180
Cellulose, 293; estimated in ex-
periments, 312, 321, 322 ; action
of dilute acids on, 290
Cell -walls, permeability of by air
when dry and wet, 88
Centaurea, irritable stamens of,
212
Centrifugal apparatus, Cambridge
Scientific Instrument Company's,
169
Cbeiranthus, for water-culture, 61
Chelidonium, stomata of, 106
Chemotaxis, 214 ; of bacteria,
216 ; of pollen tubes, 216
Chloral hydrate, used to make
leaves transparent, 22
Chlorine, estimation of in ash, 299
Chloroform, effect of on assimila-
tion, 38; on circulating proto-
plasm, 19; on stamens of Ber-
beris of, 210 ; poisonous effect
on Oxalis, 19 ; use of in pre-
serving solutions, 247
Chlorophyll, appearance in etio-
lated plants of, 54 ; effect of
acid on, 51 ; of copper on, 52,
53 ; of light on solution of, 51;
of warmth on appearance of, 55;
iron necessary for production of,
56 ; oxygen necessary for pro-
duction of, 55 ; reactions of, 50 ;
spectrum of, 52
Chloroplasts, movement of, 214
Chlorosis, 56
Chrysanthemum, warmth produced
by respiration of, 12 n.
Ciesielski on decapitation of roots,
173 ; on roots curving when
wetted on one side, 178
Circulation of protoplasm, effect of
heat on, 16, see Protoplasm
Circumnutation, 227 ; of twining
plants, 229
Clover, see Trifolium
Cobalt method of observing stoma-
tal transpiration, 104
Cocoa-butter, used for injection of
vessels, 92
Coefficient, isotonic, 128
Compression, effect on transpira-
tion current of, 92
Copper, effect on chlorophyll so-
lution of, 52
Cornus sanguinea, lenticels of, 1 10
Corylus, horizontal branches of,
196
Cotyledon, bloom of, 111
Crocus, etiolated, 57; opening
and closing in response to
changes in temperature, 219
Cross-cuts, efferct on transpiration
of, 94
Cucurbita, for assimilation experi-
ments, 31 ; peg or heel of, be-