oy 
340 
NATURE 
[ August 12, 1886 
of instances where sterility occurs in all degrees, with a 
few exceptional instances where secondary distinctions 
have been able to develop without being associated with 
the primary distinction. So that, on the whole, I cannot 
but candidly consider that all the facts relating to the 
sterility of natural species are just what they ought to be, 
if they have been in chief part due to the principle which 
Iam advocating. Mr. Darwin appears to have clearly 
perceived that there must be some one principle serving 
to explain all these facts—so curiously related, and yet so 
curiously diverse. For he says, and he says most truly, 
“We have conclusive evidence that the sterility of species 
must be due to some principle quite independent’ of 
natural selection.” I trust I have now said enough to 
show that, in all probability, this hitherto undetected 
principle is the principle of physiological selection. 
(Zo be continued.) 
RED SUNSETS AND VOLCANIC ERUPTIONS 
HE great volcanic eruption in New Zealand raises 
anew the question of the connection between yol- 
canic eruptions and sunset phenomena arising from 
attenuated matter in the upper regions of the atmosphere. 
The theory that the noteworthy sunsets about the end of 
1883 were due to the Krakatao eruption has been’ ques- 
tioned on the ground that, in many parts of the world, 
these red sunsets have continued until the present time, 
though not with the same intensity as in 1883. Beauti- 
fully variegated sunsets have always been very common 
in this country. The result was that the sunset pheno- 
mena of 1383 did not appear to us as anything new in 
kind, but only as an intensification of something with 
which we were already familiar. In order to reach a 
decisive conciusion we must have observations made in 
regions where the upper atmosphere is exceptionally free 
from vapours or other attenuated matter. The advent of 
such matter can then be detected when it could not be 
detected at other places. Among such regions I would 
suggest South Africa, especially the Cape of Good Hope. 
During my brief residence there in November and De- 
cember of 1882, nothing was more striking than the 
extreme whiteness and purity of the western twilight. If 
such a twilight is there the rule during the whole year, | 
then any diffusion of volcanic vapour in the upper atmo- | 
I would | 
sphere must produce a very striking effect. 
therefore suggest to observers in that region the value of 
precise information on this point, especially with a view 
of learning to what extent, and within what time, the red 
sunsets of 1883 disappeared, and whether any such phe- 
nomena now reappear as the result of the volcanic 
eruption in New Zealand. S. NEWCOMB 
MR. FORBES’S EXPEDITION TO NEW 
GUINEA 
Nie eee will be glad to learn that a collection 
of natural history objects has been sent to England 
by our countryman Mr. H. O. Forbes, who has_ been 
doing good work on the Astrolabe Mountains in south- 
eastern New Guinea. Unfortunately a lack of proper 
support appears to have greatly crippled the efforts of this 
energetic traveller, who fears that he may be compelled to 
abandon his proposed expedition to Mount Owen Stanley, 
the ascent of which was the primary object of his explora- 
tions on leaving England. The disaster which befel 
Mr. Forbes at Batavia, where the boat with all his equip- 
ment for the expedition was capsized and everything lost, 
will be fresh in the recollection of our readers (see 
NATURE, vol. xxxil. p. 552), and it is only by the 
utmost display of courage and energy, and by a large 
pecuniary sacrifice on his own part, that Mr. Forbes has 
been able to fit out an expedition to New Guinea from 
Brisbane. It is to be hoped that the great Societies of 
this country and Australia will not allow this expedition 
to come to an end for lack of funds. Mr. Forbes has 
shown what he can do in the cause of science, and a 
little timely help would now enable him to conduct the 
work of exploration on which his soul is bent and bring it 
to a successful issue. It is not generally known in this 
country that during his last expedition to the Malay 
Archipelago he expended more than 600/. of his own 
money in endeavouring to render his expedition more 
complete, and nothing but a little generous encouragement 
is needed to enable him to sustain the serious pecuniary 
loss which has befallen him in his attempt to reach 
Mount Owen Stanley. At the time of writing, we hear 
that there is a prospect of Australia coming to the rescue 
and aiding Mr. Forbes towards the attainment of his 
object, and we trust that England will also do something 
for a man who, as an explorer and a naturalist, has 
reflected credit on his country. 
The district recently explored by Mr. Forbes has been 
visited before by Mr. Goldie and Mr. Hunstein, the latter 
of whom has procured some remarkable novelties among 
the Birds of Paradise, which have been recently described 
by Dr. Finsch and Dr. Meyer (Zed¢tsch. Ges. Orn. ii. pp. 
369-391). Hunstein has indeed penetrated further than 
Mr. Forbes was able to do on the present occasion, as the 
latter has as yet only worked the Sogeri district from a 
height of 1009 to 5000 feet, and this only in the rainy season. 
Among the many interesting species found by Mr. 
Forbes in the Sogeri district may be mentioned Harpy- 
opsts nove-guine@, Salvad, Charmosyna stelle, Meyer, 
Psittacella pallida, Meyer (scarcely to be distinguished 
from P. drehmi of Mount Arfak), P. madaraszt, Meyer, 
Los incondita, Meyer, Parotia lawesi, Ramsay, Lophorina 
minor, Ramsay, Paradisornis rudolphi, Meyer, Ambly- 
ornts subalarts, Sharpe, Paradisea raggiana, Sclater, 
Microdynamis parra, Salvad (Rhamphomantis rollest, 
Ramsay), Melidectes emilti, Meyer, Rallicula rubra, 
Schlegel, and many other notable species, amongst which 
are two which appear to be undescribed, viz., 
Melirrhophetes batest, sp. n. 
M. similis J7. ochromelani, Meyer, sed fascia supra- 
oculari cervina distinguendus. Long. tot. 9°3, culm. 1°35, 
ale 48, caude 4:2, tarsi 1°15. 
Pseudogerygone cinereiceps, sp. n. 
P. similis P. favilaterali, Gray, ex Nova Caledonia, sed 
minor, et rectricibus haud subterminaliter albo-fasciatis 
distinguenda. Long. tot. 3°4, culm. o-4, ale 1°9, caude 
1'2, tarsi 0°65. 
It was a little unfortunate for Mr. Forbes that 
Mr. Hunstein should have visited the Horse-shoe 
Range so shortly before the arrival of the former 
in New Guinea, but it says much for the complete 
way in which Mr. Forbes does his work of exploration, 
that he should have obtained specimens of nearly every 
one of the new species discovered by Mr. Hunstein. 
Unfortunately the Birds of Paradise were out of colour at 
the time of his visit, but the specimens sent are of great 
interest, as showing the moults and changes of plumage 
in these birds. Of the extraordinary species known as 
Prince Rudolph’s Bird of Paradise (Paradisornis rudolpht) 
with blue wings and blue flank-plumes, Mr. Forbes 
secured only one, apparently a female. As these surpris- 
ing novelties have been discovered in the Astrolabe 
Range, which has an elevation of less than 5000 feet, 
what prizes and discoveries may not be awaiting the ex- 
plorer if he reaches Mount Owen Stanley with an altitude 
of 13,e00 feet? May he succeed ! 
R, BOWDLER SHARPE 
THE PERSISTENT LOW TEMPERATURE 
T is seldom that the weather maintains such a decided 
persistency for temperatures below the average con- 
ditions. Week after week passes, and the thermometrical 
