204 
appeared I proceeded to examine them as carefully as pos- 
sible, in order to see whether there were any male organs 
concealed either within or in their neighbourhood, but I 
searched in vain. In March 1883 the plants had covered 
the whole space allotted to them, and were then cut down. 
Branch after branch was once more submitted to the 
closest inspection, and the existing fruits, numbering 20, 
were collected. Of these 20 fruits I examined 5, and 
found that 3 had perfect embryos ; 10 were sown in pots, 
but only 3 germinated ; the remainder of the crop I still 
have in my carpological collection. 
The plants soon began to sprout anew, and were again 
carefully searched whenever time and weather would 
‘llow it. They were cut off in December 1884, giving a 
crop of 54 fruits, which were disposed of in the following 
manner:—Examined, 10, 7 having perfect embryos; 
sown, 20; germinated, 9; kept in salt solution, 24. 
The third period lasted till February 1886. Both plants 
were very vigorous, and had produced a large number of 
flowers, so that I collected no fewer than 137 fruits, of 
which Io were examined (5 were good), 20 were sown, 
(8 germinated, the young plant being now about 6 inches 
high) ; the remainder will be sent to different botanical 
gardens within the tropics, in order that my experiments 
and observations may be repeated under the most favour- 
able circumstances possible. 
Since February the plants have grown a good deal; 
one is flowering and has already four fruits. 
From the very outset of my observations I had noticed 
that these fruits appeared only on the thickened end of 
the flowering rachis, which is always the lowest part of the 
pendent inflorescence, as I have described in the first 
section of this paper. I cannot help thinking that this 
circumstance has something to do with the production of 
these fruits in general. 
I must observe that the numbers 20, 54, and 137 of the 
fruits collected are not the total numbers of fruits pro- 
duced by the plants in each period ; for the earlier fruits 
fell off and got lost long before I gathered the crop. 
Whatever may have been this loss, it is certain that there 
was a constant and very notable increase of fruits. I am 
sorry I omitted counting all the flowering spikes at the 
time when the plant were cut down, so as to be able to 
compare their number with that of those bearing fruits, 
and to find out, at least approximately, whether both 
groups of numbers were reciprocally proportionate, or 
not so. 
Be this as it may, ¢here zs no denying the fact that many 
Jemale plants produced in three successive years an 
increasing number of fertile frutts without the operation 
of any fertilising pollen from a male flower. 
The reader will remember that the nearest group of 
Disciphania is at a distance of about nine miles from 
Caracas. I am quite positive about this point, being 
well acquainted with the vegetation in the environs of the 
city. Now it is incredible that under such circumstances 
and in this species, which has neither showy flowers nor 
any perceptible smell, the pollination could have been 
effected by insects. It is furthermore certain that my 
plants of Disciphania are the only ones in Caracas, and 
that for this reason there is no specimen nearer to them 
than the few spontaneous ones which may grow in the 
ravine of Guarenas.!. And even if there had been any 
pollination from outside, how is it that plants, which are 
known to be extremely prolific under normal circum- 
stances, should produce such very scanty crops, although 
grown under the most favourable conditions ? 
For these different reasons I hold that the possibility 
of pollination from a male plant is entirely out of the 
question, and may fairly be discarded 
But it is likewise impossible that pollination could have 
taken place with material produced by the plants them- 
t It is interesting that the second species of Disciphania (D. lobata, 
Eichl.) appears likewise to be an exceedingly rare plant, as may be inferred 
from an observation of of Prof. Eichler’s, in the article mentioned before. 
NATURE 
[ Oct. 7, 1886 
selves, as no rudimentary male flowers, nor auxiliary 
stamens, have been discovered on them during the most 
scrutinising search in three successive years; nor was 
there ever found one single grain of pollen on the hun- 
dreds of stigmas that were inspected in the course of this - 
investigation. I well remembered Karsten’s criticism of 
Alexander Braun’s paper on parthenogenesis in Ca/edo- 
gyne, and was, accordingly, very scrupulous to establish 
beyond all question the absence of any pollen-producing 
organs. Iam fully convinced that I should have found 
them, if any had really existed. : 
In another respect I was unable to arrive at a positive 
result. I could not make sure whether the embryo is 
developed as an outgrowth from a cell of the nucellus, 
as Strasburger has found in Ca/ebogyne, or whether it is 
the development of an unfertilised oosphere. As, how- 
ever, the former case appears to be always connected 
with polyembryony, which does not occur in the seeds of © 
Disciphania, it seems to me more probable that in this 
plant we have an instance of the second case, or of true 
parthenogenesis, certainly not as the rule and normal 
modus of reproduction, but as an exception, and a very 
rare one, a kind of makeshift of nature, as it were, when 
the co-operation of the fertilising material cannot be 
realised. 
In Prof. Weismann’s essay, “ The Continuity of the 
Germ-Plasma,” there is a chapter on the nature of par- 
thenogenesis, which abounds in suggestions which, in my 
opinion, throw much light on the case under considera- 
tion. I quote the following sentence from Prof. Moseley’s 
abstract in NATURE, vol. xxxiii. p. 157 :—“‘If a special 
supply of nourishment reaches the germ-plasma, this in- 
creases in amount by growth, and thus. obtains the mass © 
requisite to start the ontogenetic process, with the 
result that parthenogenetical development takes place.” 
Strasburger had already pointed out that an analogous 
result may be arrived at by specially favourable condi- 
tions in the supply of food, which counteracts the insuffi- 
ciency of the germ-plasma. May we not suppose that — 
something similar happens in Désczfhania? Besides the — 
herbaceous branches, the club-shaped rachis of the spicate — 
inflorescences abound in proteids, and consequently there — 
must be a specially abundant supply of food, which may ~ 
have some particular influence on the growth of the ovary — 
and its contents. And it is on those places we find pre- 
cisely the fruits for which I claim a parthenogenetic origin. — 
Caracas, June 7 A. ERNST 
P.S.—Since the foregoing article was sent to England, 
I have made the following observation, which, I think, 
gives additional strength to my view as to the probable — 
cause of parthenogenesis in the case under consideration. — 
On one of my plants I had noticed two rather short in- 
florescences (4 and 5 centimetres long), with but 3 and 4 i 
flowers respectively, dut having a very much thickened, 
almost club-shaped, rachis, which measured at the apex 
nearly 3 millimetres each way. The idea struck me that 
on these spikes very likely some fruits would appear, and I iq 
marked them out for the sake of further inspection. Zy _ 
anticipations have been fully realised, as on each of the 
two there is now one ovary increasing in size, measuring — 
already 3 millimetres by 2, so that there is every reason 
to expect their final development. ) 
At the same time I may mention that on the second © 
plant, which has just begun to flower, I have found on ~ 
one spike a ¢e¢ramerous, and on another a fentamerous, 
female flower ; both spikes were very small, and had only 
two flowers. A. ERNST @ 
Caracas, June 23 
OUR ENGLISH TEMPERATURES 
PERIOD of warm weather, lasting for three weeks, 
set in over the whole of the United Kingdom about 
August 24, and continued until September 14, over nearly 
