NATURE 
menting gave more striking results than that proposed by 
Askenasy, who kept the hyacinths in the dark until the whole 
inflorescence had opened, then cut off the upper part of the 
flower-stalk with half of the flowers and exposed it to daylight, 
while the others remained in their dark place. But he also saw 
that the latter flowers remaine ! less coloured. 
Experiments were also made by me with Aucuba japonica, 
which plant produced white flowers in the dark iastead of 
purplish-brown ones in the liyht, just as the lilac does when cul- 
tivated in winter by florists. On the other hand, flowers of 
Crocus vernus and Tulipa gessneriana did not perceptibly change 
their colour. Among the leaves I experimented upon, I mention 
a Coleus which in the light produced green leaves with red lines, 
whereas the same sort gave in the dark yellow leaves with almost 
colourless lines. Achyranthes behaved very curiously, producing 
inthe dark two normally coloured leaves, but the new-formed 
internode which supported them was almost white instead of red. 
This result calls to mind that of Batalin, who found (‘‘ Acta 
horti petropolitani,” t. vi.) that plants of Polygonum Fagopyrum, 
which he had raised from seeds in the dark, were quite colourless, 
so that the difference from those grown in the light is very 
great, the latter, as is generally known, being of a dark red 
colour. 
It appears from these examples, that those organs which are 
put into the dark in a very undeveloped state (so that they must 
much enlarge there) undergo much discolouring, whereas those 
parts that are hidden in a more advanced stage of growth, lose 
less colour, in some cases almost none. 
Lilacs, for instance, develop in the dark from qu'te small studs, 
and so do flowers of Aucuba. Buck-wheat plants grow from 
small seeds containing a small hypocotyl, :hat enlarges afterwards 
to an exceedingly long part. ‘Ihe above-mentioned colourless 
long interaode of Achyranthes came from a very small stud. In 
all these cases there can be only a small quantity of pizment (or 
chromogene) in the part before its development, and only this 
small quantity seems to be spread over the same part when many 
times enlarged. These cases, accordingly, render it very pro- 
bable that light is necessary to increa-e the quantity of pig- 
ment, and that the pigment present, originates from the time 
when the plant was exposed to sunlight, 
But tulips, hyacinths, crocuses, berries of Aucuba, &c. lose 
very little of their colour in the dark. Why is this? Because 
the buds of the flowers named, when hidden in the bulb are 
quite complete, and the green fruit of Aucuba had reached 
nearly their natural size at the time they were deprived of light. 
I think these flowers and fruits had already stored up a great 
deal of chromogene which they received from the leaves during 
the time when the bulb and the fruit were formed, just as they 
possessed a sufficient quantity of food to reach perfect develop- 
ment of all parts in the dark. 
According to this opinion, the colour of a flower, fruit, leaf, 
&c, when grown ia the dark, depends only on the quantity of 
colour-making matter or chromogene that is contained in the 
part at the moment when it is withdrawn from the light, This 
opinion is supported by an observation of Askenasy’s (Bot. 
Ztg., l.c.), who found that buds of Pulmonaria officinalis in 
different stages of development, when placed into the dark, got 
their colours the more perfectly the larger the buds were at the 
time of darkening. The buds which were smallest at that time 
exhibited almost white flowers. 
My conclusion is then, that light is necessary for forming, if 
not the colouring matter itself, yet a matter (chromogene) which 
can easily pass into the pigment. J. C. CosTERus 
Amsterdam, March 12 
The Electrical Resistance of Carbon under Fressure 
I Am indebted to Mr. Herbert Tomlinson for drawing my 
attention to his most interesting comparisons between the 
behaviour of carbon and of metals in respect of change of 
electric resistance under mechanical stress, and am glad to see 
that his delicate determinations entirely support my c mclu-ion 
that the excessively slight change of specific conductivity pro- 
duced by stress in hard coke carbon cannot possibly explain the 
great variations of resistance observed in the carbon telephone, 
carbon rheostat, &c. I have also learned that a similar conclu- 
sion was arrived at some time ago by Professors Naccari and 
Pagliani, and that some experiments made by Prof, W. F. Bar- 
rett of Dublin on the buttons of compressed lamp-black prepared 
in Edison’s laboratory for use in his well-known carbon tele- 
+. 
March 23, Bie 
phone lead to a precisely similar result. 1 am therefore perfectly 
willing to admit that before the publication of my experiments — 
this question was virtually settled. It is quite clear that the 
carbon telephone does not work by any variation in the specific 
resistance of the carbon, but by the partial opening and closing 
of the circuit at certain surfaces where the intimacy of the con- 
tact can be varied by the vibrations. 
Bristol, March 20 Sitvanus P. THOMPSON 
Vivisection = 
As Iam named in your article thus headed (p. 429), I shal 
be obliged if you will permit mea brief explanation of my posi” 
tion in regard to the question. ‘Ihere is doubtless in point of 
suffering a very great difference between such experiments on 
animals as those tabulated by Prof. Yeo (and cited in your 
article) and those common upon the Continent, and of which the 
horrible tortures perpetrated by Professors Schiff, Mant 5 
and Paul Bert may be taken as fair types. But I fail to see by 
what means, whether lezi-lative or otherwise, the atrocities of 
vivisection are to be prevented, while its more moderate practices 
are to be permitted. TJlad the sins of the experimentalists been 
confined to the ‘‘ hypodermic injection” of a few mice, as Sir 
James Paget has tried hard to make the public believe, I venture 
to assert that no outery would ever have been raised on the sub- 
ject. I for one should certainly have thou ht the cause unworthy 
of support. But the truth is, unfortunately, far otherwise. It 
is not against the inoculation of ‘‘ vermin,” or the pricking of a 
‘*tadpole’s tail,” that the indignation of the English people has 
been stirred, but against the prolonged and exquisite torments to 
which such highly sentient creatures as horses, dogs, and other 
domestic animals have been and still are subjected, often under 
the influence, not of chloroform, but of curare. So long 
as English physiologists coninue to cite these things with 
approval, and openly to regret that the effects of public 
opimion in this country are such as to throw obstacles in 
the way of ‘‘free” and unlimited vivisection, as practised 
in the Continental schools, so long, I apprehend, the agitation 
deprecated in your article, will go on, and gather strength. It 
is the influence of public opinion only, which in this country 
finds expression as it does in no other, that has hitherto pre- 
vented the physiological laboratory of England from becoming 
as notorious a scene of hovror as that of France, Italy, or Ger- 
many. And, let it be borne in mind, that the stir on this subject, 
which has expressed itself recently in the pages of various 
reviews and magazines, was set going by the demand of the 
Medical Conzress for unrestricted vivisection. Sir William 
Gull’s opening sentence in the Wineleenth Century of this month 
is, therefore, wide of the mark. Not less does he mis-state the 
case, when, in the course of his conclading observations, he 
infers that I bring against physiological research the charge of 
Atheistic tendency, That charge is distinctly made by me, not 
against legitimate research of any kind, but against a method 
which I wholly dissociate from ‘‘science” properly so called. 
And it is a charge not lightly made, but based on sound expe- 
rience and thoughtful observation, unbiassed by “ emotion” of 
any kind. 
As it has not been my privilege to escape the customary per- 
sonal retort of pro-vivisectors with regard to the wearing of 
fur, feathers, and the utilisation of animals, whether for food, 
pleasure, or clothing, I shall hold myself indebted to your 
courtesy for permission to make the following statement in justi- 
fication of my own consistency:—I never buy furs, feathers, 
ivory, kid gloves, stuffed birds or other creatures. I have long 
been engaged in trying to introduce the use of vegetable leather 
for making boots aud shoes, and have devoted much of my time 
to the question. I detest all ‘‘sport” which necessitates the 
pain and suffering of living creatures, and have writen many 
articles and letters to various journals for several years past 
against seal-huating, pigeon-shooting, coursing, battues, and 
rabbit-gins. Of late years I have added “ vivisection”’ to the 
list. My husband’s horses wear no bearing-reins ; and I never” 
see cruelty without interfering at the risk—as I know but too 
well—of personal insult. Finally, it is twelve years since I 
tasted flesh or fowl of any kind. ANNA KINGSFORD 
11, Chapel Street, Park Lane, W., March 16 
[It seems a somewhat unwarranted and unworthy argument 
that because some foreign experimenters have been guilty of 
excess, therefore we are totally to suppress in England that which 
all competent persons know and declare to constitute a most im- 
——ooOooo 
