THE 
juty 24, 1875.] 
GARDENERS 
CHRONICLE. 
103 
VENUS’ FLY-TRAP. 
By Tuos. А. С. BALFOUR, M.D.,F.R.S.E., F. R.C.P,E, 
(Continued from p 
July 1, 1874.—A_bluebottle бум was made to walk 
slowly over the leaf of a fresh specimen of Dionza 
without any contraction occurring ; the leaf was again 
irritated by the fly and now began to contract at a very 
slow rate, so much so indeed that part of the body of 
of an inch below the margin, begins, the ciliary spines 
gradually separate from each other and bend back- 
wards, in егесине = the eversion ог retroversion 
of the margins of the 
How long does the анаа continue? This is 
very much influenced by the amount to be di 
Thus in two instances, where a fl 
э 
on the seventeenth day. 
with meat more than twenty-four days were required, 
The average time of contraction seems to be between 
two and three weeks, 
know anything of the nature and cause of 
; where eiie of the leaf of the Dionza occurs. 
dien is one of great interest, as pointing 
analogy between the animal and 
| AS regar 
. bility lead to the Бена t confess our 
ignoranc i 
ansmission 
- I spoke of co- bc power in the closing of the 
l two blades ; now does this'reside in the hypothetical 
- central organ, and may we, under any circumstances, 
have this action interfered with? Mr. Darwin has 
stated that he can produce this condition (a kind of 
win is still more interesting 
Dr. зае s, pie it points to the possibility 
of even a higher analogy than his, Ido not know 
_whether the paralysed leaf was on the same Lese which 
was pricked, or whether there was a cros of the 
Given on "eg authority 
. of such an able and careful experimenter, we need 
not hesitate to accept it, thoug n 
state that I have not as yet bete able to 
point referred to. I have made punctures in different 
spots, but have never seen the operation followed by 
non-closure of one blade 
= OnJuly 4I се а Dionza leaf near the central 
| рч = it closed naturally. 
.. July 6.—Leaf open pep onded to stimulus 
‘both blades closing. У P 
Only the other day I pricked with a point of a 
fe а portion of the midrib, almost where the petiole 
Ф 
pE 
; 
a 
& P. 
uly 17.—Leaf decidedly more open at the petiole 
ets "n the part beyond that at which the cut ter- 
тау 2o —Part still open, but has been closed by 
irritatio 
Tos = 3.—Open at end again 
The blades in this case site d in harmony, and 
though the leaf did gd open oes this seemed owing 
to the ang gen 
On July 22, to я Бен is influence might not 
be маі i om the root, I cut the midrib of the 
The leaf remained open after this operation, 
but was closed on irritatio 
July 23.—Leaf open to ir half the lashes to-day. 
Xd чы —At 3 P.M. leaf half open, closed оп 
ES continued to do só on July 27 and August. т. 
nar — are two kinds of cells, the one exhibiting 
he power of eee cde d the ot Бе the power of 
distension, and tha ese are situated, though ina 
rse order, at he еба of the leaflets апа the 
pulvina ed tex же the ee x" ing 
bove in case and below in the other, and 
consquently Фе. place ice É in the one case 
above and in the pulvi оу ; апа as the over 
distension of the other kind of cellsis, in his view, the 
t vement, the leaflets are 
Deus to take an upward direction, while 
falls down ; каа. ri thinks that his y 
the effects of cutting the lower vent: of the pulvinar, 
which would interrupt the process on which his theory 
is founded. 
Dr. Carpenter adopts these views, and applies 
them to the explanation of the closing of the Dionæa 
leaf. as a the Sensitive 
from the lower edges of the midrib and yet the 
as closed, so that some other dem ect than that 
of c contractile and distensible cells is he 
e of contraction 
e circinate быа which they 
TA te being dévélope ow if this process 
d n these kinds of cells. к are we to believe 
that qon can perform directly opposite functions ? 
2: ko the two sets of cells ch laces ? 
dly, are no ж 
is just a reversa 
ey ecessary in the other case, "res ini 
tion? Besides, in the case of Dion 
tensible cells at the lower portion of the midrib effect 
he closure of the marginal bristles, which are an 
ime uis vi this wonderfnl contrivance for en- 
trapping in 
No ainas pex of which I am aware, 
is satisfactory. ght be allowed to throw = 
a suggestion, I Should Е аза : look for the 
planation of the closing rather e doeet vessels 
which are very abund die Dion and Drose 
and which from their distribution ae rhe gement 
d to play an important part. I shall only ‘natant 
he peculiar expansion of the spiral as it enters the 
аерды head of the > hai ir of Drosera dichotoma or 
inata. We know that elasticity 
iral, t consequently it may either con 
expand according to forces applied to i; 
ening of 
to 
will explain all the ei. but they m 
very important place. I have spoken of the abundant 
spirals in Dionza and Dro and I 
of Mr. S , who ven m 
ing the microscopic structure ants; 
and any one who knows his remarkable skill an 
v B = preparing — for me ener ng 
derstand the peculiar satisfaction which I 
Men in iated with me hes 
to the minute structure of these plan 
But to return from this digression, from the midrib 
of the Dioni we have at short distances spirals pass- 
ing off at right angles across blades entering 
the interior of the spi: r i They 
to the very end of the spines, but we have not 
even 
er t how they termi there. But 
on might help us to understand how the 
and spines might be 
this r 
Da "т. of blades 
eff. 
But while we contemplate the marvellous but 
of e wii ан of the de "45 pn ust own aot i sealed 
they have been м Sm being quite R n heda of Resort s 
view, there was теке 0 1 which seemed vete ѕирро 
some 
portion of the upper part of the petiole ay - 
descend as the Tx emen bus the 
weakening of ve base o we should have expected 
it to have gone d ova Дайе cm 
secret —t ста the irritability and con- 
traction, and m the — Phage z P 
in th w ole contrivance w a peak- 
able satisfaction of kno ing, ir: as iu. ex- 
grins ар, that ** This ideo! eh forth hom the Lord 
of H 5, who i is wonderful in counsel and excellent in 
odán € 
3. Se E believed = the viscous fluid 
secreted was a of nectar, to allure the insect to 
the sensitive d st the leaf ; but this view is entirely 
insect, and it sometimes does no 
ur till about гола ог атр eros hours after that 
evt though it appears to o be кес found 
at the end of twenty-four lose 4f not sooner. Pro 
fessor боги, who very kindly examined some > of the 
secretion E me, informed contained no 
etion w 
I inform you 
nalysis uch a and I can only add that I 
feel most ы to ve for having do done so. 
the secretion of 
of 
ca rufa; and Will has s 
principle in certain ven specially in Bombyx 
of this ata and that it occurs 
creature, 
and, на at is specially interesting to us, in vomi 
matte 
But it has also been found in d peni for it occurs in 
and == some species, m 
ced by the сө ате, аз 
name implies, pec ау o severe, In the plants in 
which it is found it is generally regarded as sf result 
of rari See and this seems d in the case 
of Pinus Abies, by the fact det: iti 
; a 
ne 
found in oil of turpentine ; and w 
kept in leaden vessels crystals of саа of lead are 
sometimes fou 
When the fruit of Sapindus Saponaria and that of 
Tamarindus indica are distilled with water and sul- 
rup 
b. oxidation of tartaric 
fruit; and Dobereiner Ms 
acid + distilling ten parts o rans асі 
arts of bin erp ms падане е апі 
+ phe te parts o 
Formic acid can bird be — from vegetable 
products ; thes, starch and s when oxidised by 
manganese a jeld it, It is also got 
by the actio x oil of vitriol on ligneous tiss 
arb 
it a current of electricity. ut though it might easily 
be formed in plants, it € not as yet been often atc 
en e и the ets interest in this 
Mr. Andre Мау hà article in the сано 
erige for r Septembe er last year, takes Dr. Hooker 
ask e carnivorous habits 
ot "n Dione: 
attached too weight to the statemen 
рз М ае of the difficulty, PEE two questions 
Sin emi ferr : 
the secre ver present until 
bean sapoe 2" id sngwet lay say utl dou. 
remember of ha seen it que 
as I said aisi alge some inie ti iir Мыс o 
after fet hus 
that if the plant be 
Е: 
erely the exudation of the juices of = 
he are distinctly a acid? 
е. 
+ whether mere Yep would cause this 
appe 
(To be continued.) 
- * "The name of Professor Dewar is the bes карй M ^ 
accuracy of this analysis. 
