500 
NATURE 
2 
[Marcu 25, 1897 
the forest proper. Other introductions, some of which are 
extremeiy abundant, may be briefly noticed. The beautiful 
Orcus chalybeus, from Australia, is now widely spread and very 
common, feeding on Lecanzum, Pulvinaria, Diaspis, &c. 
Rhizobius ventralis, Muls., from China and Ceylon, attacks that 
most abundant scale Lecanéum dlongulum, and other species. 
Chilocorus ctrcumdatus, from China and Ceylon, breeds freely on 
scales in Honolulu. Trees literally covered with JZyéz/aspzs were 
entirely cleaned. Even the old dry scales were turned over in the 
search for food. Platyomus lividigaster has bred freely on orange 
Aphis in the city. Scymmnus debilis, which in California feeds on 
Dactylopius, has become entirely naturalised. Other introduc- 
tions, which have bred in the Islands, are Chzlocorus bivulnerus, 
Leis conformis, Synonyche grandis, and Novius Koebelez (Fig., 
Rep. on Import. of Par. and Pred. Ins., by State Board 
of Horticulture, Sacramento, 1892.) There is little doubt that? 
other introduced species will turn up, when the city gardens and 
suburbs are systematicallysearched. Before the introduction of the 
species above mentioned, the only known Hawaiian Coccznellide 
were a few species (probably endemic) of Scyznws and Coccinella 
abdominalis, the latter, no doubt, accidentally imported from 
America many years ago. Unfortunately this species is 
attacked by a hymenopterous parasite, a Avaconid, Centistes 
americana, Riley, which may interfere with the splendid work 
of C. vepanda. The presence of this parasite is the more to be 
deplored, as such care was taken to exclude parasitised 
specimens when the introductions were made. This was very 
necessary, as the ladybirds seem very liable to the attack of 
parasitic Hymenoptera, especially the Australian species. 
It is very pleasing to be able to refer to such successful 
results in the Hawaiian Islands, as in the United States Mr. 
Koebele’s work has met with a good deal of adverse criticism. 
But it is not only by the introduction of ladybirds that Mr. 
Koebele has done such signal service, for he has had many other 
insect pests to contend with, which it is beyond the power of 
these to affect, attacking, as they do, but a very small portion of 
the insect world. In many parts of the islands, the bananas 
and palm-trees have been severely attacked by the larva of a 
species of Pyralzdina. There is little doubt that in course of 
time this plague will be entirely kept under by a fine Chalcid 
(Chalets obscurata, Walk.), introduced from China and Japan, 
which has already multiplied enormously at the expense of 
these caterpillars—so much so, indeed, that in many localities 
the trees have now entirely recovered. Again, within the last 
few years a Lamellicorn beetle (Adoretus ambrosus) has been 
introduced from Japan. This insect speedily multiplied pro- 
digiously, and soon destroyed nearly every rose-tree in Hono- 
lulu, and subsequently attacked the foliage of many other trees. 
The cultivation of roses—once a feature of the city—became 
impossible, while a remedy seemed hopeless. One day, how- 
ever, Mr. Koebele discovered a parasitic fungus, and _ by culti- 
vation of this, and infecting healthy beetles, soon spread it far and 
wide. Whether the fungus will prove entirely effective is not at 
present certain, but in any case it will be a most useful aid. The 
writer has seen the ground under trees which were attacked, 
literally strewn with dead beetles—all killed by the fungus— 
and beneath the surface of the soil the larve had likewise 
perished. It is at least certain, therefore, that myriads of the 
beetles were destroyed very shortly after the fungus was spread 
around by the individuals that had been infected. 
It becomes natural to ask why the success of the imported 
beneficial insects has been so pronounced here, while in other 
countries it has been attained in a comparatively small measure. 
The reason, I think, is sufficiently obvious. The same causes 
which have led to the rapid spread and excessive multiplication 
of injurious introductions, have operated equally on the beneficial 
ones that prey upon them. The remote position of the islands, 
and the consequently limited fauna, giving free scope for increase 
to new arrivals, the general absence of creatures injurious to the 
introduced beneficial species, and the equability of the climate, 
allowing of almost continuous breeding, may well afford results 
which could hardly be attained elsewhere on the globe. The 
keen struggle for existence of continental lands is comparatively 
non-existent, and, so far as it exists, is rather brought about by 
the introduced fauna than by the native one. 
In conclusion, I cannot help turning to the darker side of the 
picture. What will be the result of all these importations on 
the endemic fauna? The introduction of many other species— 
1 Since writing the above several other species have been found, which 
have evidently bred in the country. 
NO. 1430, VOL. 55] 
parasitic and predaceous—is contemplated, and will be per- 
formed. That success, from an economic point of view, will be 
attained there is little doubt, and while industries are threatened, 
or even the gratification of eesthetic tastes, it is certain that no 
consideration will be given to the native fauna. When even 
now the ladybirds are affecting the latter, what will be the re- 
sult of the introduction of more widely predaceous species ? The 
effect of the former is not imaginary, but proven. In June 
1895, ina lovely forest in Hawaii—sooo feet above sea-level—I 
found the native trees much affected by a black Aphis. By 
beating these trees the blight came down in abundance, and 
amongst them various fine species of endemic Chrysofa and 
Hemerobius, predatory creatures. One or two introduced 
ladybirds were also noticed. By September the ladybirds were 
in thousands, the blight and native insects in small numbers. 
In August 1896 not an Aphzs was to be found, and only one or 
two stray specimens of ladybirds, as one may find anywhere 
throughout the forests. They had done their work and dis- 
appeared. ‘This is a high testimonial as to the capabilities of the 
beetles, and as the existence or non-existence of Hawaiian 
Chrysopa is not likely to be regarded by people at large, and 
seeing that sooner or later the greater part of this most interest- 
ing native fauna is, under any circumstances, in all probability 
doomed to extinction, it only remains to wish Mr. Koebele a 
success in the future equal to that which he has already attained. 
Honolulu, H.1I., November 1896. R. C. L, PERKINS. 
MARINE ORGANISMS AND THE CONDI- 
TIONS OF THEIR ENVIRONMENT: 
THE ocean may be divided into two great biological regions, 
viz. the superficial region, including the waters between 
the surface and a depth of about 100 fathoms, and the deep-sea 
region extending from the 100 fathoms line down to the greatest 
depths. The superficial region may be subdivided into two 
provinces, viz. the shallow-water or neritic province around the 
land masses where the depth is less than 100 fathoms, and the 
pelagic province, embracing the superficial waters of the ocean 
basins outside the 100 fathoms line ; these two provinces con- 
trast sharply as regards physical conditions, which are of great 
variety in the neritic province, and very uniform over wide areas 
in the pelagic province. 
Temperature is a more important factor in determining the 
distribution of marine -organisms, mostly cold-blooded, than in 
the case of terrestrial species, mostly warm-blooded and air- 
breathing animals, the distribution of which depends rather upon 
topographical features than upon climatic conditions. 
A map was exhibited showing the range of temperature in the 
surface waters of the ocean all over the world, and indicated 
northern and southern cireumpolar areas with a low tempera- 
ture and small range (under 10° F.), and an almost circum- 
tropical area with a similar small range but high temperature ; 
in temperate regions the range is greater, the areas of greatest 
range (over 40° F.) being found off the eastern coasts of North 
America and of Asia and south of the Cape, due to the mixture 
of currents from different sources, which sometimes causes the 
destruction of enormous numbers of marine invertebrates and 
fishes. 
The pelagic tropical waters of the ocean teem with various 
forms of life, of which probably 70 to 80 per cent. function as 
plants, converting, under the influence of sunlight, the inorganic 
constituents of sea-water into organic compounds, thus forming 
the original source of food of marine animals both at the surface 
and at the bottom of the sea. 
The number of species living in the pelagic waters of the 
tropics may greatly exceed the number in polar waters, where, 
on the other hand, there is often a great development of indi- 
viduals, so that there is probably a greater bulk of organic matter 
in the cold polar waters than in the warm tropical waters. The 
rate of animal metabolism is slower at a low than at a high 
temperature, and organisms inhabiting tropical waters probably 
pass through their life-history much more rapidly than similar 
organisms living in polar regions. Carbonate-of-lime-secreting 
organisms are most abundant in the warm tropical waters, 
decreasing in numbers towards the polar regions, and it has 
been shown that the precipitation of carbonate of lime from 
solution in sea-water takes place much more rapidly at a high 
1An address delivered at the Royal Institution by Dr. John Murray, 
F.RS 
