Fuly 9, 1885] 
NALOR E 
219 
Amboyna, Timor Laut, Buru, and Timor. In Java, 
Sumatra, Buru, and Timor he made extensive inland 
journeys through districts rarely or never before visited 
by European naturalists ; and as he everywhere collected 
assiduously and observed intelligently, the record of his 
travels is exceedingly interesting. His special studies 
were botanical and ethnological, and in these departments 
he has added much to our stores of knowledge. His 
observations on the manners and customs, the myths and 
superstitions of the various tribes among whom he resided 
or travelled will be of great value to anthropologists, 
owing to the wide range of his observations and the time 
and trouble he devoted to the inquiry. In zoology he did 
not collect largely, and indeed it was simply impossible 
for him to do so, since the continuous Jabour and atten- 
tion needed to form a well-preserved herbarium in the 
damp equatorial climate and while almost constantly 
moving about, leave the traveller but little leisure to 
devote to other departments of natural history. To 
collect effectually in any wild tropical country, the natur- 
alist should settle himself for at least six months at a time 
in a good central position from which short excursions in 
various directions can be made; and if these head- 
quarters are well chosen it is possible to obtain an almost 
perpetual “fine season,” and thus greatly increase both 
his collecting power and his personal enjoyment. 
Mr. Forbes appears to have had rather more than his 
fair share of accidents to his collections, and in every 
case what was lost was of especial interest. His insect 
collection from the Keeling Islands was destroyed on the 
way back to Java, and we thus lose the opportunity of 
comparing the list with that made by Mr. Darwin more 
than forty years before. In Timor Laut a large part of 
his herbarium was destroyed by fire, while a smaller col- 
lection made in the interior of Buru was actually left 
behind for want of porters to carry it. The Timor Laut 
collection is especially to be regretted, as it was obtained 
with great difficulty in perhaps the least known island of 
the whole archipelago, while it is probable that many 
years will elapse before any other naturalist will venture 
to explore so remote and inhospitable a country. 
Mr. Forbes’ residence for three weeks in the Keeling 
Islands enabled him to note what changes had occurred 
since Darwin’s visit nearly half a century earlier. These 
are very slight, and seem incompatible with the theory 
that any subsidence has taken place, because the inner 
margin of some of the islands next the lagoon are some- 
times half a mile distant from the outer edge, and the 
greatest cyclones do not carry the coral dééris nearly so 
far. It is now generally admitted that the celebrated 
“ subsidence theory” of the formation of atolls and barrier 
reefs is unsound as a general explanation of the facts ; 
yet it so fully and plausibly explained all the details of 
coral structure known at the time, as to command uni- 
versal acceptance and unbounded admiration. We have 
here a remarkable instance of the danger of founding a 
general explanation of widespread phenomena on an 
assumed basis, for the fact of long-continued subsidence, 
which was the very foundation of the whole theory, was 
in most cases quite incapable of proof. It is also now 
apparent that the theory was to some extent inconsistent 
with the views as to oceanic islands which Darwin him- 
self originated and which are now generally admitted to 
be sound. His great argument, that no single oceanic 
island possessed ancient stratified rocks or contained a 
single indigenous mammal, was equally an argument 
against the view that the widespread coral archipelagoes 
of thé Pacific and Indian Oceans were due to the sub- 
sidence of co-extensive tracts of land, since it is almost 
impossible that all the higher points of these submerged 
lands, spread over nearly half the surface of the globe, 
should be without exception of volcanic origin. 
Crabs of two or three species were the most abundant 
terrestrial inhabitants of the Keeling Islands living in 
narrow corkscrew burrows, which are so numerous that 
one hundred and twenty of their holes were counted in 
an area only two feet aquare. Around these holes little 
mounds are formed, and the crabs carry into their burrows 
twigs of trees, pieces of seaweeds, seeds, &c., thus fulfilling 
in many ways the functions of earthworms in this newly- 
formed land. Their numbers are enormous, and Mr. 
Forbes thus describes the curious optical effect produced 
by them :— 
“On placing the foot on the region occupied by them, 
one perceives an undulation of the surface followed, over 
a circular area, by a surprising change of the pure white 
ground into a warm pink colour, which for the moment 
the stranger puts down to some affection of his eyes from 
the reflection of the light. He soon perceives that this 
movement is caused by the simultaneous stampede of the 
dense crowd of the peopled shore into their dwellings, 
just within the door of which they halt, with the larger of 
their two pincer-claws, which is of a rich pink colour, 
effectually barring the entrance except where one watchful 
stalked eye is thrust out to take an inquiring look if the 
alarm is real. As one advances the pink areas again 
change into white, as the Crustaceans withdraw into their 
subterranean fastnesses. On traversing a broad field 
occupied by these crabs, the constant undulations and 
change of colours produce a curious dazzling effect upon 
the eyes.” 
During his long residence in the mountains of Java, 
Mr. Forbes made many interesting observations on the 
fertilisation of orchids. He was surprised at the large 
number of these plants which, though often possessing 
the combined attractions of showy flowers and fragrant 
odours, yet never or rarely produce seed-capsules. In 
one case, for example, out of 360 flowers examined till 
they withered or dropped off, only six produced capsules. 
Again, he finds a considerable number of species with 
showy flowers which are yet specially adapted for self- 
fertilisation and never seem to be visited by insects. The 
most extreme and marvellous example of this phenomenon 
is found in a plant related to Chrysoglosswm, which 
fertilises itself without ever opening its flowers at all. 
Mr. Forbes observed these plants in the forest as well as 
in numerous specimens grown in a garden, and all were 
fertilised in the same way; and he adds :—“ In opening 
the locked-up petals, I found the labellum beautifully 
marked with lines of purple, carmine, and orange, and 
the column also ; but no insect eye could ever be fascinated 
or allured by its painted whorls.” 
These observations are of extreme interest, and they 
certainly prove, as Mr. Forbes remarks, that the rule 
“that the flowers of orchids are fertilised by the pollen of 
their flowers,” is by no means so universal as has been 
supposed. Yet the phenomenon does not seem so extra- 
ordinary if we look upon it as one of the normal phases 
