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Full text of "A naturalist on lake Victoria, with an account of sleeping sickness and the tse-tse fly"

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A NATURALIST ON 
LAKE VICTORIA 

WITH AN ACCOUNT OF 
SLEEPING SICKNESS 
AND THE TSE-TSE FLY 



PLATE I. 
Acraeijxp modelj. N y mphuxUihe. mxmics. 




E.C Kni|ht del.et ehromo Hath imp 

MODEL SPECIES OF PLANEMA WITH MIMETIC FORMS OF 

PSEUDACRAEA EURYTUS. ^/sruxt size. 

Keprodjjbcedb by perrruLssion/ of the Entoinoloqical Soccefy of Londoiv- 

(Ft ntispiace-J 



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( ORIA 



I aTAJ*! 

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,eTi*aa ^d idgusO 

.LLQL ,zi 

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.Siei ,11 81 .baelal filkguS , ? jjtuod^io mioi 2ist^twa .el .:t 

.Oiei ,iir7 61 .addeitaa , t) JoUh»o»«v .V\ .S 
.aaviJan 'aniagiW .iQ io eno ^d itdgoaO 

.8IGI ,111 1 jbnjslel asmaW , 't* ♦^ai'io^ mioi e«i^"twa .z^ .8 

.J^IGI ,iV eS tbnalel eraoH , $ ftkn«>o»w .5^ .7 

.21G1 ,iix 9 (bflfilel b1IǤ08. , ? euj^aaWtii miol ewi\j'vwa .a^ .B 

.^L9A ,111 51 (bn^lgl ogBlua , $ iaig'goc^^ i*! .G 

.liGl ,111V 8r , ? ^^\iio3'9'Qoc^ mtol ?.Mi\v-vwa .2*1 .01 
a^Bi8eH ,nogia .iM io dooi *89w lijan avBsM .A .8 x^f ftdgOioO 



. ND COMPANV 





PLATE I 

'Planema tellus ? , Kome Island, L. Victoria, 12 vm, 1914. 

Caught by native. 

2. Pseudacraea eurytus form terra ? , Damba Island, 1-15 

IX, 1911. 

3. PI. epaea form paragea ? , Bugalla Island, 24 ii, 1912. 

4. Ps. eurytus form obscura ? , Bugalla Island, 18 ii, 1912* 

5. PI macarista ^ , Entebbe, 16 vm, 1910. 

Caught by one of Dr. Wiggins' natives. 

6. Ps. eurytus form hobleyi ^ , Wema Island, 1 iii, 1918. 

7. PI. macarista ? , Kome Island, 29 vi, 1914. 
•"8. Ps. eurytus form tirikefists ? , Bugalla Island, 6 Xil, 1912. 

9. PL poggei $ , Bulago Island, 15 iii, l9iL\^ J0l^'! 

10. Ps. eurytus form poggeoides ? , 13 Viii, 1911. 

Caught by S. A. Neave near west foot of Mt. Elgon, Eastern 
Uganda. 



A NATURALIST 
ON LAKE VICTORIA 

WITH AN ACCOUNT OF SLEEPING 
SICKNESS AND THE TSE-TSE FLY 



^ u 



^ 



^'L 



BY 



G. D. HALE CARPENTER 

D.M., B.Ch. (Oxon), Uganda Medical Service 

Fellow of the Linnean, Entomological, and Zoological Societies 

of London 



WITH 2 COLOURED PLATES, A MAP, 
CHARTS, AND 87 ILLUSTRATIONS 




E. P. DUTTON AND COMPANY 
68 1 FIFTH AVENUE, NEW YORK 



First published vi 1920 



(All rights reserved) 

PRtNTBD IK GREAT BRITAIN 



TO THE 
MEMORY OF MY FATHER 

P. HERBERT CARPENTER, D.Sc, F.R.S. 

AND TO MY DEAR MOTHER 

THIS, MY FIRST BOOK, 

IS DEDICATED 



" It appeal's to me the doing what little we can 
to increase the general stock of knowledge is as 
respectable an object of life as one can in any 
likelihood pursue." 

Letter from Charles Darwin to his sister, 1833. 



INTRODUCTION 

At the commencement of 1910, when studjdng Tropical 
Medicine at the London School, I was asked if I would 
undertake an investigation into the bionomics of tho 
Tse-tse fly, Glossina palpalis, in Uganda, as the Tropical 
Diseases Committee of the Royal Society had come to 
the conclusion that a greater knowledge of this fly was 
essential for the successful dealing with the disease. 

I left England in June 1910, and during the second half 
of this year and beginning of 1911 worked at Jinja, 
on the north shore of the Victoria Nyanja,^ where the 
Nile takes origin, and endeavoured to famiharize my- 
self with the novel surroundings and with the fly. 

It soon appeared that residence on the completely 
depopulated islands known as the Sesse Isles, in the 
north-west part of the lake, would afford ideal conditions 
for studying Glossina unaltered by the presence of man- 
kind and his surroundings ; accordingly, in February 
1911, I went to Nsadzi Isle, which, lying south of Entebbe 
and within two or three hours of it by canoe, had been 
recommended by the P.M.O. as suitable for a beginning. 
This island, however, did not furnish aU the conditions 
required for the investigations, and camp was moved, 
after a fortnight, to the large Island of Damba to the 
east and on the Equator, where the rest of the year was 
spent. 

^ Nyanja, not Nyanza. The former is Luganda for lake, the latter 
means nothing, and is erroneously copied from one book to another. 



X INTRODUCTION 

In January 1912, a new site was chosen on Bugalla, 
the largest island of the Sesse group, lying in the north- 
west corner of the lake, and fourteen months of unin- 
terrupted residence were spent there, after which I went 
home on leave, returning in December 1913. On arrival 
at Entebbe I met Mr. W. F. Fiske, from the States, 
who had been deputed by the Tropical Diseases Bureau 
of London to investigate Glossina morsitans, and had 
decided to first make the acquaintance of palpalis, 
the problems connected with which seemed more 
readily soluble, and by their solution might throw light 
on morsitans. He had decided, as a result of several 
months' previous work, to undertake a tour of the chain 
of islands lying parallel with the north shore of the lake, 
in order to compare one with the other, hoping that the 
presence or absence of Glossina might be found to be 
correlated with definite factors. He proposed that 
I should join him, and we made the tour together, very 
greatly to my benefit not only regarding Glossina in 
particular, but in field work in general, his wide experi- 
ence of field entomology and acute powers of observation 
showing me how much I had missed when working by 
myself. At the close of a tour of about two and a half 
months Fiske left for another part of Uganda, and I 
settled down on the western spur of Kome Isle to carry 
out a year's continuous cycle of experiment and observa- 
tion on the smaller islets within working distance 
(Ngamba, Nsadzi, Kizima, Tavu, Bulago, Kimmi). 
Unfortunately this was brought to an end by the out- 
break of war ; for in August 1914 I was called off for 
duty with the troops on the Uganda-German frontier, 
and subsequently with the Belgian Northern column 
under Colonel Molitor, which invaded German East 
Africa via Kigezi and Ruanda, to Tabora, after which 
my duties took me to various parts of German East 
Africa and Portuguese East Africa. When released from 



INTRODUCTION xi 

active service in November 1918, I returned to Uganda, 
and had a further most interesting tour among the same 
islands that were visited with Mr. Fiske in 1914. 

This book is an attempt to give an account of the 
life on the islands of the Victoria Nyanja : and very 
nearly all the examples mentioned were met with there, 
between February 1911 and August 1914. During active 
service, however, other examples were met with, an 
account of which seemed not to be out of place in this 
book because of their bearing on certain of the points 
discussed. The fascinating question of the Colouration of 
Insects has been treated at some length, but mainly from 
the point of view of the bearing on it of examples met 
with on the islands. Consequently this chapter must 
not be taken as a discussion of the relative merits of 
rival theories from an abstract, or " arm-chair," point 
of view. Similarly the chapter on Glossina must not 
be- taken as a complete summary of all that is known, 
since this book deals almost entirely with some of 
my own observations and work. 

The chapters on Mammals, Birds and Reptiles, I am 
aware, are dreadfully scanty. In defence, I can only 
urge that I am primarily an entomologist ; and my 
knowledge of field botany is a minus quantity ! 



I am indebted to the Royal Society and the Controller 
of His Majesty's Stationery Office for permission to 
reproduce illustrations and other matter that have 
appeared in my reports to the Sleeping Sickness Com- 
mission. 

The beautiful photograph of Glossina is the work of 
Mr. A. Robinson, of the Oxford University Museum. 

Grateful acknowledgment is also due to the Council 
of the Entomological Society of London, for permission 



xii INTRODUCTION 

to reproduce the two plates of butterflies which have 
appeared in the Transactions for 1920. Many of the 
observations on Insects have already appeared in the 
publications of the Society, others in Bedrock, and some 
of those on the Fossorial Hymenoptera in the Journal of 
the East Africa and Uganda Natural History Society. 

Mr. A. L. Shephard, of the Tropical Diseases Bureau, 
very kindly gave me references which were of great help 
in the preparation of the chapters on Sleeping Sickness, 
and thanks are also due to the Director, Dr. A. G. Bagshawe, 
C.M.G,, in this matter. Dr. H. Eltringham most kindly 
complied with a request for the use of his talent as a 
draughtsman, and provided an original and humorous 
drawing of an imaginary example of mammalian mimicry. 

To my friend and mentor, E. B. Poulton, F.R.S., 
Hope Professor of Zoology at Oxford, I owe more than 
I can say for his ever ready advice and encouragement, 
for his kindness in writing the Preface, and in 
particular for reading the MS. of Chapter XI, and 
suggesting improvements therein. To him and Dr. S. 
A. Neave are due the selection and arrangement of 
specimens illustrating by two plates forms of Pseudacraea 
eurytus and their models. Dr. Karl Jordan, of the Tring 
Museum, was most kind in showing me Lord Rothschild's 
collection of this wonderful species, including a unique 
specimen of a new form which shows the geographical 
range to extend further southwards than has been 
known hitherto. 

G. D. H. C. 



PEEFACE 

BT 

PROFESSOR POULTON 

Every reader of this book will, I feel sure, recognize 
that it contains a really wonderful body of observations ; 
especially so if the brief time in which they were made 
be borne in mind — from February 1911 until the day 
in August 1914 when, without a word of preparation or 
a hint of warning, the author arrived in Entebbe to find 
in full progress, and to bear his part in, the fiercest struggle 
of human history. And even this short period of " island 
life " was broken into by nearly a year's leave. 

The observations recorded, whether dealing, now and 
then, with men, or, throughout the book, with other 
animals, are both loving and accurate. The two qualities 
are closely associated, for the love of living beings renders 
the patient study of them an unceasmg fascination and 
delight. 

Apart from the chapters on Sleeping Sickness and its 
carrier, the Tse-tse fly, the most important discoveries 
are those which add to our knowledge of Papilio dardanus, 
and, above all, the breeding experiments which brought 
final confirmation to the conclusions of Dr. Karl Jordan 
upon that wonderful series of mimetic butterflies here 
proved beyond doubt to be forms of a single species — 
Pseudacraea eurytus of Linnaeus. 

xiii 



xiv PREFACE 

It is a curious fact that the African butterflies — far 
less numerous in species than those of the tropical East, 
and outnumbered even more by the American — should 
include what are probably the two most remarkable 
examples of mimicry in the world — Papilio dardanus 
and Ps. eurytus ; furthermore, that they should illustrate 
such different aspects of the subject. 

The Swallowtail, dardanus, whose non-mimetic male 
is accompanied by a very similar non-mimetic female in 
Madagascar, the Comoro Islands, Somaliland, and Abys- 
sinia (although two single but different mimetic females 
were once taken in this last locality), is represented, 
wherever it occurs on other parts of the African continent, 
by females entirely different from males, and either 
mimetic of other butterflies, or, far more rarely, inter- 
mediates between these mimetic forms, or persistent 
stages enabling us to retrace the history of their origin. 
Until 1903 the mimetic females were all believed to 
resemble the commonest Danaine butterflies of each 
locality — often mimicking in a single area three different 
species with widely different patterns. 

This interesting and complicated story became still - 
further involved, when, on October 7, 1903, the late Mr. 
Roland Trimen brought before the Entomological Society 
an account of a new and entirely different female, mimick- 
ing not a Danaine, but an Acraeine model, belonging to 
the genus Planema. For some years the new mimic, 
appropriately named planemoides, was only by strong 
inference assumed to be a form of dardanus, but definite 
proof was soon afforded by the study of a specimen 
captured by Mr. T. T. Behrens, R.E., near the old southern 
boundary of Uganda on the west shore of the Victoria 
Kyanja. This single example was, on the left side, a 
gynandromorph, viz. one of those rare individuals in 
which the patterns of the two sexes occur combined. 
In this case parts of the yellow and black non -mimetic 



1 



PREFACE XV 

pattern of the male are, as it were, let into the mimetic 
female pattern, clearly proving that the two belonged 
to the same species. The specimen, now m the Hope 
Collection of the Oxford University Museum, is figured 
in the Transactions of the Entomological Society for 1906 
(PI. XVIII, Fig. 4). 

The evidence of this specimen was very satisfactory, 
but how much better was the proof by breeding from a 
known parent, obtained by the author in Bugalla island, 
Sesse Archipelago, when he captured on December 1, 1912, 
a planemoides female, and reared from its eggs three 
females like the parent, seven of the black-and-white 
hippocoon females, and twelve non-mimetic males. And 
later on, m 1915, when Medical Officer to the forces acting 
on the southern frontier of Uganda, he reared one plane- 
moides female, one trophonissa female (similar to hippocoon, 
but with the main white areas replaced by orange), and 
five males from the eggs of a captured female combining 
the patterns of her two daughters. These are the only 
occasions on which the planemoides female has been bred, 
although rare forms which evidently represent an imper- 
fect planemoides, many hundreds of miles away from its 
model, have been bred by Mr. C. F. M. Swynnerton in 
S.E. Rhodesia, and by Mr. G. F. Leigh, in the neigh- 
bourhood of Durban. 

The Pseudacraea mimics, belonging to the Nymphaline 
sub-family, and allied to our own White Admiral {Limenitis 
sybilla), illustrate the second great group of mimetic 
butterflies in which the males resemble models as weU 
as the females. The models of the Ps. eurytus series, 
with which this book deals, all belong to the Acraeine 
genus, Planema, but in some of them the sexes differ, 
while in others they are alike. In Uganda there is one 
common example of the first, mimicked by a Pseudacraea 
whose male resembles the male and female the female, 



xvi PREFACE 

and also two examples of the second, each mimicked by 
a Pseudacraea with sexes alike ; and when, in 1910, 
Dr. Jordan announced that these three Pseudacraeas could 
not be separated structurally from each other, from the 
Linnean West African eurytus, or from other mimics west, 
east, and south, which had been described as distinct 
species, I felt that the obvious conclusion that they were 
in fact all of them forms of one and the same species 
ought to be confirmed by breeding experiments before 
it gained acceptance. And it was the occurrence, in the 
same area, e.g. Uganda, and ex hypothesi interbreeding, 
of forms with sexes different and with sexes alike, which 
raised the greatest difficulty, and at the same time 
would prove of the deepest interest if the conclusion 
were confirmed. In order to test it I wrote to 
every naturalist known to me who was in a position 
to undertake the work, pointing out its exceptional 
interest and importance. I even tried to persuade the 
late Mr. A. D. Millar who had just been very successful 
in breeding the Natal form of the Pseudacraea, to under- 
take the journey to Uganda and apply his experience 
there. 

The complete success finally attained by the author 
on Bugalla may be gathered from the results fully set 
forth in Chapter XI. Dr. Jordan's conclusions were 
thoroughly confirmed, and the large group of conspecific 
forms, now proved to interbreed in the same areas, and 
interbreeding, it may be legitimately inferred, with those 
of other areas when they meet on the boundaries, the 
group of Pseudacraea eurytus, took its place beside that 
of Papilio dardanus as one of the greatest examples of 
mimicry in the world. 

This discovery was completed by another of equal 
importance described in the same chapter, the evidence 
that the mimetic patterns were only kept up to the mark 
in islands where and when their models were relatively 



PREFACE xvii 

abundant. As these became scarce, so did the mhnetic 
Pseudacraeas run into each other more and more 
completely through the intermediation of an increasing 
number of transitional forms. 

In concluding I should wish to take this opportunity 
of thanking all those naturalists who, during the past 
quarter of a century, in distant lands, have helped me 
in my work and have given me the great pleasure of helping 
them ; and, among all, especially to thank the author. 
Dr. G. D. Hale Carpenter, D.M., not only for the mutual 
help which may be gathered from this book, but for 
much further help in S.W. Uganda, and ex-German East 
Africa ; the late C. 0. Farquharson, in S. Nigeria, whose 
death in the sinking of the Burutu almost at the end of 
the war, was so great a loss to Natural History ; W. A. 
Lamborn, in S. Nigeria, ex-G.E.A., and now in the 
Federated Malay States ; Dr. G. A. K. Marshall, D.Sc, 
C.M.G., in Natal and S. Rhodesia ; the Rev. Canon K. 
St. Aubyn Rogers, M.A., in British and ex-G.E.A., the 
late R. W. C. Shelford, M.A., in Borneo, another grievous 
loss to science ; C. F. M. Swynnerton, in S.E. Rhodesia ; 
and C. A. Wiggins, P.M.O., Uganda, in this country 
and B.E.A. To all these and many others I offer most 
grateful thanks for some of the greatest happiness I 
have known. 

EDWARD B. POULTON. 
August 3, 1920. 



CONTENTS 




Introduction 



PA.OE 

ix 



Preface. By Professor E. B. Poulton, F.R.S. 



. xui 



CHAPTER 

I. Sleeping Sickness . . . . . 

Symptoms — Ancient description — History of the 
introduction of the Uganda epidemic — The 
Rhodesian disease 



II. Natural History op Sleeping Sickness . 
Trypanosomes, Tse-tse flies, and game 



11 



III. Natural History of Glossina palpalis 



30 



IV. The Lake . . . . . .67 

Geographical data — Scenery — Weather — A storm — 
Weather prophets — Noises of the night 

V. Canoes and a Voyage . . . .84 

Description of the Sesse canoe, and a voyage to 
the southernmost islands of Sesse 



58957 



XX 



CONTENTS 



CHAPTEB PAGE 

VI. A Tour of Investigation among the Northern 

Islands . . . . . .94 

A number of islands compared as to their fauna 

VII. Mammals . . . . . .126 

Monkeys — Hippos — Situtunga — Otters — Bats — 
Mongoose 

VIII. Birds 145 

IX. Eeptiles and Fish ..... 180 

X. The Colouration of Insects . . . 195 

Procryptic — Anticryptic — Aposematic — Directive 
marks — The habit of grouping together more 
common in aposematic than procryptic species 
— Enemies of protected insects — Sexual colouring 
and coiu-tship of butterflies — Mimicry, Batesian 
and Mullerian — Do birds eat btatterflies ? — Longley's 
revised hypothesis of mimicry 

XI. FSEUDACRAEA EURYTUS .... 242 

Some of its forms and varieties and their bearing 
on the interpretation of mimicry by natural 
selection 

XII. Hymenopteea ..... 276 

Ants — Wasps — Fossors or Sand-wasps — Bees 

XIII. Sundry Insects ..... 305 

Beetles — Di-agon-flies — Montispa — Mantidae — 
Grasshoppers — Cockroaches — Earwigs — Flies — 
Spiders — Myriapods — Crustacea — Molluscs 



LIST OF ILLUSTRATIONS 



Plate I. Model species of Planema with mimetic forms of Pseuda- 

craea eurytus (coloured plate) .... Frontispiece 

FACING PAGE 

Plate II. Model species of Planema with mimetic forms of Pseuda- 

craea eurytus (coloured plate) ...... 244 

Fly beach on Damba Isle ........ 24 

Fly beach on Bugalla Isle ....... 24 

On Damba Isle ; not a good fly shore ..... 30 

A fly-boy at work ......... 30 

An Ambatch tree ......... 48 

Fly beach on Kimmi ........ 48 

Glossina palpalis and pupae ....... 54 

Uprooted tree on Kimmi Isle forming ideal shelter for pupae . . 54 
Searching for pupae among grass tussocks on south point, Bulago 

Isle 54 

Tree trunk on Bugalla Isle under which many Glossina pupae could 

always be found ........ 56 

Breeding place of Glossina at hollowed base of tree on Bugalla . 56 

" Enzibaziba " bushes on Damba Isle forming breeding ground . 58 
Shingle and sand under sheltering Enzibaziba bushes where flies 

have been seen to deposit larvae ..... 58 

The first artificial breeding ground, on Ngamba Isle ... 62 

Artificial breeding ground on Tavu Isle ..... 62 

The Kagera river . . . . . . . . .68 

The head of Napoleon gulf where the Nile arises from the Lake . 68 

The eastern cataract of the Ripon falls ..... 68 

The birth of the Nile 68 

Young Raphia palm ......... 70 

Wild date pahn 70 

A tangled mass of Ipomaea in flower ..... 70 

A bed of bracken on Bugalla ....... 70 

Abrupt margin of forest belt on Bugalla ..... 72 

Park land on Bugalla ........ 72 



XXll 



LIST OF ILLUSTRATIONS 



My settlement on Bugalla Isle, 1912-13 

Aerial roots dipping to ground, Bugalla forest 

Giant twisted stem of creeper, Bugalla forest 

Canoe returning with load of firewood 

A canoe race ..... 

A halt on the east coast of Bugalla . 

Pitching camp on the isthmus of Kirugu Isle 

The western point of Kirugu Isle 

On Kirugu Isle 

On Kirugu Isle 

The high ridge of Kuye Isle 

South end of Buguye Isle 

South end of Nkose Isle . 

Canoe off Kirugu Isle 

Bulago Isle, north bay and forested north point 

The open grass land interior of Bxilago 

Large fig tree on Ngamba Isle 

Nsadzi Isle, south beach . 

Dwasendwe from Dwanga Mto, 

Kisigalla Islet . 

South beach of Nsadzi Isle 

South-west end of Wema Isle 

View South-east from Bugalla camp . 

Wee Man choosing a grasshopper 

Wee Man and Tommy taking grasshoppers 

Wee Man being rude to a Tortoise 

Tommy and Wee Man in an interval of a game 

Puffin " hating " a Tortoise 

A favourite haunt of Situtunga on Bugalla 

A bat caught on tent at Jinja 

Nest of Egjrptian goose 

Nest of stone curlew 

Nest of stone curlew 

Nest of Osprey 

View from camp on Kome 

View towards Buvumira from Bugalla camp 

Nesting place of kingfishers 

Fly-catcher 

Nest of crocodile 

Canoe-man with Enswa-swa 

A small Enswa-swa . 

A very abundant tree frog 

Fly-boy and Mamba 

Semutundu . . 



FACING PAGE 

74 

78 

78 

84 

86 

86 

88 

88 

90 

90 

90 

90 

92 

92 

94 

94 

98 

100 

106 

106 

106 

106 

118 

132 

132 

134 

134 

136 

142 

142 

150 

150 

152 

160 

166 

166 

170 

174 

174 

182 

190 

190 

192 

192 



LIST OF ILLUSTRATIONS 



XXlll 



Male .... 

Caterpillar of Aterica galenc 

Pupae of Papilio dardanus 

Moth at rest on low foliage 

Aposematic caterpillars 

Diagram of ant and typical spider 

Imaginary case of Mammalian mimicr 

" Toby " as a caterpillar (Pseudacraea eurylus) 

" Toby " as a chrysalis {Pseudacraea eurytus) 

View to the West from Bugalla camp 

House on Bugalla, 1912-13 

Interior of Bugalla house . 

Back of house on Kome Isle, 1914 

Front of Kome house 

Fly-boys' camp on Kome Isle, 1914 

Servants' huts on Kome Isle, 1914 

Cook's hut and kitchen on Bugalla 

Personal boys and their wives . 



PACING PAGE 

192 

196 
198 
198 
206 
228 
228 
262 
262 
278 
282 
282 
292 
292 
304 
304 
314 
314 



CHARTS 



I. Comparison between climates of Entebbe and Bugalla Isle 
II. Influence of climate on flies at Jinja .... 

III. Influence of climate on the fly . 

IV. Influence of climate on rate of reproduction of the fly 



V. Number of female flies on different islands 
VI. Nmnber of male flies on different islands . 
VII. Number of crocodiles and flies on Tavu island 



40 
42 
44 
46 

At end behind map 



TABLES 

Parallelism of Nagana and Sleeping Sickness . . . . 

Prolonged catching of flies increases proportion of females caught 

Proof that the fly roams along the coast . 

Sources of non-mammalian blood found in wild flies 

Flies watched biting captive crocodile 

Number of butterflies on various islands 

Food of Bee-eaters ...... 

Numbers of eggs in nests of crocodiles 

Degrees of relationship between model and mimic 



PAQE 

25 

31 

33 

37 

38 

125 

172 

182 

233 



xxiv LIST OF ILLUSTRATIONS 

PAGE 

Some forms of Pseudacraea eurytus, their models, and distribution 254 
Pseudacraea eurytus on Damba Island ..... 257 

Forms of Ps. eurytus obtained by breeding from laiown parent 
Models, mimics, and intermediates in varying proportions . 
The same shown graphically as a chart .... 
Models and mimics in different localities .... 



264 
265 
267 
274 



MAP 

The Sesse Archipelago . . . . . - . At the end 



A NATURALIST ON 
LAKE VICTORIA 

CHAPTER I 

SLEEPING SICKNESS 

In this chapter a general account will be given of the 
history and symptoms of Sleeping Sickness as it was 
known during the epidemic in Uganda. It may be said 
at once that the disease is entirely confined to tropical 
Africa, nor does there seem any reason, as will be 
explained later, to fear its spread beyond Africa. 

In a few words it may be said that the cause of the 
disease is a minute unicellular creature, called a Trypano- 
some, belonging to the lowest order of animal life, which 
is as it were inoculated by the bite of a blood-sucking 
fly, the " Tse-tse," or Glossina. 

A common history given by patients who suffer from 
Sleeping Sickness is that they have been in a country 
where they were much bitten by Tse-tse flies, and that 
after a few days a painful swelling has appeared on the 
neck, accompanied by high fever. The swelling may 
appear to be on the point of becoming an abscess, but does 
not do so, and gradually subsides. It is probable that 
this represents the site where the fly which was the 
cause of the infection actually bit. The fever may 
subside in a few days, and recurs at irregular intervals 
lasting weeks or months : it often reaches a high point 
attended with delirium. 

2 1 



2 SLEEPING SICKNESS 

There is a good deal of headache, debility and languor, 
and vague pains in legs. An interesting feature is the ap- 
pearance of an erythematous rash, mainly on the chest 
and back. There is great wasting and enlargement 
of the glands of the neck. Another interesting feature is 
puffy swelling of parts of the face and body : this (ede- 
matous swelling is a particular feature of the diseases 
of animals, which are, as will be seen, so very closely 
connected with Sleeping Sickness. 

This condition may go on for years, and has been 
known to disappear altogether with an apparent cure ; 
it is known as " Trypanosomiasis." Next comes the 
stage to which the term " Sleeping Sickness " more 
properly applies. The drowsiness becomes accentuated, 
so that the subject takes no interest in his surroundings 
and does not trouble to eat, though he will eat food 
if it is brought him, and he is fed. The fever continues 
irregularly, the eyes become more pufEy, the lips and 
tongue tremulous, the wasting more and more pro- 
nounced, until death finally supervenes with the patient 
in a state of coma. At the last there may be mania 
and convulsions. 

It has been noticed that natives suffering from Sleeping 
Sickness appear to feel the cold very acutely, and will 
often sleep so near to a fire that they inflict severe burns 
on themselves. This also shows how the senses are dulled, 
so that one can conclude that they cannot suffer 
much. 

Death may occur in a few months after the initial 
fever, but more usually after one to three years. 

The earliest account of Sleeping Sickness which is 
known in print dates from 1742, and is of considerable 
interest because it reflects the current medical opinion 
of the day. 

Dr. E. D, Whittle, in the Malay Medical Journal 
for April 1911, drew attention to a book by a naval 



EARLIEST ACCOUNT OF SLEEPING SICKNESS 3 

surgeon named John Atkins, called Physical Observa- 
tions on the Coast of Gainey. 

The following extract is given in The Sleeping Sickness 
Bulletin : 

" The Sleepy Distemper (common among negroes) 
gives no other previous Notice, than a Want of Appetite 
two or three Days before : Their Sleeps are sound, and 
Sense of Feeling very little ; for pulling, drubbing, or 
whipping, will scarce stir up Sense and Power enough 
to move ; and the moment you cease beating, the Smart 
is forgot, and down they fall again into a state of Insen- 
sibility, driveling constantly from the Mouth, as if in a 
deep Salivation ; breath slowly, but not unequally, nor 
snort. 

** Young People are more subject to it than the Old ; 
and the Judgement generally pronounced is Death, 
the prognostick seldom failing. If now and then one 
of them recovers, he certainly loses the little Reason he 
had and turns Ideot. 

" The immediate Cause of this deadly Sleepiness in 
the Slaves, is evidently a Super-abundance of Phlegm 
or Serum extravated in the Brain, which obstructs the 
Irradiation of the Nerves ; but what the procatartick 
Causes are, that exert to this Production, eclipsing the 
Light of the Senses, is not so easily assigned. 

" We find sometimes in Europe that Enormities in 
the Non-Naturals, Surfeiting and Drunkenness do gradu- 
ally, as Age and Custom advance, weaken the Tone of 
the Brain, to the Admission of serous and extrementitious 
Humours, including Sleepiness, etc. But here the Case 
is different, they being young People that are generally 
afflicted, and who have been destitute of the Means of 
Surfeiting. 

" I shall ascribe the Cause to catching Cold, and their 
Immaturity ; to Diet and Way of Living ; and to the natural 



4 SLEEPING SICKNESS 

WeaTcness of the Brain ; some or all of these Causes co- 
operating to it. 

" First. In Immaturity , or Childhood, it is a common 
and true Observation, that more of Phlegm and recre- 
mentitious Humour is bred, than at Manhood ; because 
the Fibres, and consequently the Faculties resulting 
from, their Constitution, have not attained their due 
Spring and Perfection ; and it is only supposing the 
Africans continue longer Children than the Europeans. 

" Secondly. Promoted here by their Diet and Way of 
Living. At Home it is mostly on Roots, Fruits, and 
Herbage, greedily devouring such as are wild and uncul- 
tured ; which, together with the intolerable Heats of the 
Sun, weakening the concoctive Faculty, together with 
their Inactivity, render a very recrementitious Nutriment : 
Their Indolence is such (when shipped on Board for Slaves) 
as to be entirely dispassionate at parting with Wives, 
Children, Friends, and Country, and are scarcely touched 
with any other Sense or Appetite, than that of Hunger ; 
and even in this, for want of Custom or Instinct, they 
cannot distinguish proper Food, nor know when to leave 
off, voraciously eating though Victuals be never so dirtily 
cook'd ; and whether the Flesh be raw or dressed, whether 
of the Guts or a Sirloin ; a Practice also that may sometime, 
by over-stretching the Fibres of the Stomach, occasion 
Crudity and indigestion. By their Sloth and Idleness 
the Blood becomes more depauperated ; and those recre- 
mentitious Humours bred from it, that Exercise would 
throw off through the proper secretory Organs, are here 
disposed towards the weakest Part, which in the Gener- 
ality of Negroe Slaves I take to be the Brain. 

" Thirdly, The natural Weakness of the Brain, I am apt 
to think the principal Cause of the Distemper. Doubt- 
less that Part gains Strength by Exercise, i.e. by the 
Employment of our rational Faculties, as well as the 
Muscles and external Fibres of the Body by Labour ; 



EARLIEST ACCOUNT OF SLEEPING SICKNESS 5 

and since the Africans are hereditarily ignorant, destitute 
of all Art and Science, or any mechanical Knowledge to 
exercise the Brain, it consequently grows weaker in its 
inward Structure and Recesses ; and falls together with 
the Judgement and Passions. 



" The Cure is attempted by whatever rouzes the Spirits ; 
bleeding in the Jugular, quick Purges, Sternutories, 
Vesicatories, Acu-Puncture, Seton, Fontanels, and sudden 
Plunges into the Sea, the latter is most effectual when 
the Distemper is new, and the Patient not yet driveling 
at Mouth and nose." ^ 

Noteworthy in this account are the number of causes 
assigned to this mysterious disease, and the naive way 
in which the author assigns the conditions to " some 
or all of these causes " ! 

The essential characteristics of the disease in an advanced 
stage are all noted ; the " Indolence," " State of Insensi- 
bility," ''Hunger," ''Sense of Feeling very little," 
but the preliminary stages were not noted, for Atkins 
says it gives no other notice than a want of appetite two 
or three days before ! 

With the aid of a little imagination one can see a 
terrible picture of these wretched, somnolent natives 
being subjected to " pulUng, drubbing or whipping " in 
the endeavour to give them sufficient " Exercise " to 
" throw off the recrementitious Humours " and afterwards 
" voraciously eating though Victuals be never so dirtily 
cook'd " ! 

The " Sudden Plunges into the Sea " are not used 
for curing Sleeping Sickness at the present day ! 

^ The Navy Surgeon : or Practical System of Surgery ivith a Disserta- 
tion on Cold and Hot Mineral Springs and Physical Observations on the 
Coast of Guiney, by John Atkins, Surgeon. London ; Printed for J. 
Hodges, at the Looking Glass, over against St. Magnus Church, London 
Bridge. aiDCCXLII. pp. 364-7. 



6 SLEEPING SICKNESS 

It was, I believe, well known to the African slave 
traders that natives with enlarged glands were of no use 
to them, as they always died and could not be made to 
work. So they were careful not to take any in this 
condition, but nevertheless took, without knowing it, 
many cases who had the earliest stages of the disease, 
and the American slave-owners used to find their slaves 
dying of this peculiar drowsiness. 

Yet it was not infectious, that is, it was not communi- 
cated from one to another : the reason for this will be 
entered into more fully further on. 

In 1890, a French doctor discovered in the blood of 
a patient from Africa who was suffering from a peculiar 
fever, a microscropic organism which he recognized as 
a Trypanosome, but he did not establish any relation 
between this and the fever, and the credit of first dis- 
covering this belongs to an Englishman. In 1901 Dr. 
Forde, in the Gambia colony on the West Coast, had 
an English patient with a peculiar fever of a chronic 
and irregular type. He found in the blood a curious 
organism whose nature he could not recognize, and 
called in the late Dr. Dutton, who at once recognized 
the creature as a Trypanosome ; ^ the first one to be 
discovered in man, though one had been described as 
the cause of a disease in horses in India some ten years 
before. 

At first, and for some time, Sleeping Sickness was only 
known to occur in West Africa, but when equatorial 
Africa was gradually opened up the disease found its 
way into Uganda with disastrous results. 

This is believed to be due to Stanley's expedition for 
the relief of Emin Pasha, which in 1888 travelled from the 
Congo to the Lake Albert Nyanza. In 1891 the Sudanese 
soldiers of Emin's force were brought into South Toro 

1 British Medical Journal, 1902, January 4th, p. 42, and November 29th, 
p. 1741. 



THE UGANDA EPIDEMIC 7 

with their followers, and eventually were brought into 
Uganda itself to be under control. 

In July 1901, Dr. Albert Cook of the Church Missionary 
Society at Mengo (Kampala) noted eight cases of a mys- 
terious disease, and six months later reported that on 
Buvuma Island over two hundred natives had died and 
thousands appeared to be infected. The mortality 
became appalling, and the Government were at their 
wits' end, for it seemed as if the whole population was 
doomed. 

In July 1902, the first Royal Society Commission arrived 
in Uganda, composed of Drs. Low, Christie, and Castellani, 
and Colonel Sir David Bruce arrived in February 1903. 
On April 28th, it was announced that the disease was 
caused by a Trypanosome and conveyed by a Tse-tse fly, 
Glossina palpalis.^ 

It was suggested at once that as the haunts of this 
fly were strictly limited, it would be easy to check the 
disease by removing the population ; ^ but the natives, 
with their characteristic fatalism, refused to leave their 
villages along the shores of the lake. In the mean- 
time the disease raged unchecked, and by the end of 1903 
the number of deaths had reached over 90,000 ; whole 
villages were being depopulated, and great tracts of 
highly cultivated country relapsed into scrub and forest. 

In March 1905 Lieutenant Tulloch, R.A.M.C, who 
had been sent out by the Royal Society to help in the 
investigations, became infected with the disease in its 
virulent form, and died a few months later. 

By November 1904 the epidemic had appeared on 
the shores of Lake Albert in North-West Uganda, and a 
survey of Uganda by six specially appointed medical 
officers in 1905 showed that the banks of the lakes and 



^ Reports of Sleeping Sickness Conunission of the Royal Society, 
1903, Nos. I, IV. 
* See Bulletin of Sleeping Sickness Bureau, vol. 4, pp. 241-2. 



8 SLEEPING SICKNESS 

watercourses throughout Uganda were infested with 
the Tse-tse fly. 

Statistics furnished in a dispatch by the Governor 
showed that " during the last five years the total mor- 
tality from this scourge in this Protectorate has consider- 
ably exceeded 200,000."i 

Sir Hesketh Bell also reported *' the natives have been 
almost completely wiped out everywhere along the lake 
shore, and in the islands the mortality has been even more 
appalling. Buvuma, for instance, which a few years ago 
was one of the most thickly populated and prosperous of all 
the islands, counted over 30,000 inhabitants. There are 
now barely 14,000. Some of the Sesse group have lost 
every soul ; while in others a few moribund natives, 
crawling about in the last stages of the disease, are all 
that are left to represent a once teeming population." 

In November 1906, it was again suggested that the 
only way to save the people was to remove them into 
fly-free areas, and segregate the infected natives into 
camps. The aid of the chiefs was sought and the matter 
fully explained to them, compensation was made to the 
heads of evicted families, they were given land away 
from the infected areas, and by degrees not only the 
mainland shores of the lake, but the islands also, were 
cleared of their population, so that by 1909 all these were 
deserted and going back to the wild state. ^ 

Great difficulty was experienced in preventing the 
natives from returning to their homes, and some managed 
to obtain canoes and cross back to Buvuma and Damba 
Islands, but at length the evacuation was finally completed, 
and at the present day the whole of the fertile and valuable 
island territory is abandoned to the Tse-tse fly. 

But the lake shore can only be kept in this condition 
by stringent regulations and penalties, and a few natives 

1 Dispatch No. 218 from Sir Hesketh Bell, November 1906. 

2 See Bulletin of the Sleeping Sickness Bureau, vol. 4, pp. 241-2. 



THE RHODESIAN DISEASE 9 

are frequently discovered in the forbidden areas by the 
patrolling canoes. 

By these means the inhabitants of Uganda were saved, 
and at the present day there are very few deaths a year ; 
from 1905-1917 there were just over 30,000 deaths for 
the whole of the Uganda Protectorate. 

At the end of 1909 considerable alarm was caused 
by the discovery in Nyassaland of Sleeping Sickness 
(or rather. Acute Trypanosomiasis) in a native there, 
and since then a number of cases have been found, some 
of them Europeans, in Nj^'assaland, North-East Rhodesia, 
and Portuguese East Africa : in the case of some natives, 
they had certainly never left their homes. This was 
very interesting from a scientific point of view, because 
Glossina palpalis, the species of Tse-tse which carries 
Sleeping Sickness in Uganda and the West Coast, does 
not exist in those countries. 

It was soon found that the carrier was another species, 
namely, the very one which has been so long known to 
travellers in Africa as the cause of Tse-tse fly disease or 
" Nagana " of horses, cattle and dogs. 

This species is known as Glossina morsitans.^ 

As this new form of human Trypanosomiasis appeared 
to be very much more acute than the form known as 
Sleeping Sickness, the discovery was disconcerting. It 
is, however, possible that our ideas of the severity of 
this form of Trypanosomiasis will need to be modified 
in the light of further knowledge, for during the campaign 
in East Africa a number of natives were found to have 
Trypanosomes in their blood while under treatment 
for other complaints, and appeared to be little the worse 
for their presence ; these natives had not been in the area 
of Glossina palpalis, so that either the Trypanosome was 
gambiense carried by morsitans, or else it was rhodesiense 

^ Kinghorn and Yorke, Annals of Tropical Medicine and Parasitology, 
1912, vol. 6, pp. 1-23. 



^^ SLEEPING SICKNESS 

in a non-lethal form. It is of interest to note here that 
a case of true Rhodesian Trypanosomiasis has recently 
been recorded as the first to be cured by treatment ; 
hitherto this form had always been regarded as fatal.i 

vLt ^^^''^''^.^■J-^ode^iense infection which recovered. Daniels and 
Newham, British Medical Journal, 1919, November 8th, p. 829. 



CHAPTER II 

NATURAL HISTORY OF SLEEPING SICKNESS 

I PROPOSE now to deal at greater length first with the 
Trypanosomes and next with the Tse-tse flies, then the 
inter-relation of the two will be considered and the relation 
of both to the wild animals of the countries in which 
they occur. 

Trypanosomes are not " microbes " in the accepted 
sense of the word as commonly used ; that is, they are not 
micro-fungi, but belong to the Protozoa, the lowest members 
of the animal kingdom. The Protozoa can be divided 
into four main groups, in each of which are found species 
causing disease in man and other vertebrates. The 
Sarcodina is exemplified by the well-known Amoeba and 
the species known as Entomoeha, which causes dysentery. 

The next group, Mastigophora, is the one with which 
we are most concerned at the moment, since to it belong 
the Trypanosomes and their allies. The name, which 
means " Whip Bearers," refers to the possession of one 
or more lashes or Flagella, which by their rapid move- 
ments draw or push the animal through the fluid in 
which it lives. 

The third great group of Protozoa is the Sporozoa, which 

is only too familiar through the various species that 

cause malaria. To the last group Infusoria belong the 

myriad forms which are the delight of the amateur 

microscopist and may be seen so easily in stagnant water. 

One species, Balantidium, is a cause of dysentery. 

11 



12 NATURAL HISTORY OF SLEEPING SICKNESS 

Let us now look a little more closely at the MastigopTiora. 
The group is divisible into six sub-groups, ^ but only that 
which includes the Trypanosomes need be mentioned 
here. This is named Protomonadina, and includes the 
following genera : 

1. Trypanosoma. — There is a single flagellum arising 

near the posterior nucleus and continued forwards 
as a marginal flagellum of an undulating mem- 
brane ; usually continued into a free flagellum. 
The species are found mostly in blood and in the 
digestive tracts of invertebrates, but are also forms 
in the life cycle of species wholly parasitic in 
insects. 

2. Trypanoplasma. — There are two flagella, the posterior 

one united to the body by an undulating membrane 
along most of its length. According to their 
mode of life they fall into three groups. 

1. Parasites in the blood of fresh- water fish 
and in the digestive tract of leeches. 

2. Parasitic in the digestive tract of marine 
fishes. 

3. Parasitic in invertebrates. 

3. Crithidia. — A single flagellum arises about the middle 

of the body and runs forwards to form the marginal 
flagellum of a short or rudimentary undulating 
membrane, and is continued beyond as a free 
flagellum. 

Crithidia occur as parasites in the gut of insects 
or as a stage in the life cycle of a Try- 
panosome. 

4. Lepfomonas or Herpetomonas. — There is a single 

anterior flagellum but no undulating membrane. 
These are parasitic on invertebrates, chiefly 
insects, but also occur as a form of the next genus 

^ This classification is taken from Minchin. 



TRYPANOSOMES 18 

in invertebrate hosts or in artificial cultures. It 
is also of great interest that they are found in the 
milky juice of certain plants (EupJiorbiaceae). 
. 5. Leishmania. — There is no flagellum, but there are 
two nuclei as in the other genera. These animals 
have become specialized to live in the tissue cells 
of vertebrates and so have no need of organs of 
locomotion. It is of much interest that in arti- 
ficial cultures Leishmania develops into forms like 
the two preceding genera or like Trypanosomes. 
The type species causes a fatal disease in Asia 
known as " Kala-azar." 

Now let us consider a little more fully the Trypanosomes 
themselves. They are elongated bodies with a pointed 
posterior extremity where is a small nucleus, and at the 
anterior extremity the whip-like flagellum which by vigor- 
ous movements drags the Trypanosome along. The 
undulating membrane pursues a wavy course along the 
body and is responsible for the name, which is derived 
from rpvTTavov, meaning a carpenter's tool : the allusion 
is probably to the spiral thread on an auger. In the 
middle of the body is a large nucleus. T. gambiense 
in the blood is several times as long as the diameter of a 
red corpuscle, but much narrower. The different species 
that may be found in the blood vary very greatly in size 
and activity ; gambiense is not very active and merely 
wriggles, but a species such as vivax in goats can hardly 
be kept in the field of a microscope. The first one to 
be seen was found in the blood of a frog, but the 
first reliable description was not given until 1841, when 
a specimen was described from the blood of a trout. ^ 
Not until 1879 was one found in a mammal, and this was 
Trypanosoma lewisi, seen in the blood of the rat. It is 

1 By Valentin. Recent work by Mile. M. Gauthier, however, placoa 
this species in the genus Trypanoplasma. 



14 NATURAL HISTORY OF SLEEPING SICKNESS 

now known that in nearly every place rats are infected 
with this species, often to the extent of 50 per cent., but 
it is not harmful to them unless present in great numbers. 
The first disease-producing Trypanosome described was 
T. evansi, which kills numbers of horses, camels, elephants 
and dogs in Asia and North Africa by causing a disease 
known as " Surra " ; it was discovered in 1880. Not 
until 1895 was the next pathogenic species discovered, 
and this was an extremely important one, the know- 
ledge of which was of the utmost help to the subsequent 
investigations into Sleeping Sickness. 

This species was named T. brucei, after Sir David 
Bruce, who proved it to be the cause of " Tse-tse fly 
disease " or " Nagana " in South Africa.^ 

In 1901 another species was described as T. equiperdum, 
the cause of " Dourine " in stallions, brood mares, and 
donkeys in America and North Africa. Also in 1901 
was discovered T. gambiense, the first Trypanosome to 
be known for a cause of disease in man.^ 

In 1902 T. equinum was shown to be the cause of *' Mai 
de Caderas," a fatal disease of horses in Brazil and the 
Argentine Republic. Another human Trypanosome was 
discovered in 1909,' by Chagas ; it causes in children, 
and adults who have not become immune in childhood, 
chronic fever, enlargement of the thyroid gland, and 
puffiness of the face, and may rarely result in death. 
This species was found to differ sufficiently in its life- 
history to be put in a new genus, and has been named 
Schizotrypanum cruzi. In 1910 it was shown that the 
cause of the acute Trypanosomiasis of Rhodesia was 
differentiated, not by its morphology, but by its effects 

^ Preliminary Report on the Tse-tse fly disease or Nagana in Zulu- 
land, 1895. 

* British Medical Journal, 1902, January 4th, p. 42. 

8 Chagas, Brazil Medico, 1909, April 22nd. See Bull. Inst. Pasteur, 
1909, May 30th, pp. 453-4. Also Bulletin of the Sleeping Sickness 
Bureau, vol. 1, p. 252; vol. 2, p. 117. 



TRYPANOSOMES 15 

upon animals, from its close allies T. gambiense and T. 
bruceiy and it is now known as T. rhodesiense.^ 

In 1913 another species was found in man, causing 
in natives of Nigeria a chronic swelling of the glands in 
the neck very like the earliest stages of Sleeping Sickness, 
but very rarely going beyond that ; it has been named 
T. 7iigeriense.^ 

It must not be thought that every Trypanosome is a 
cause of disease. This is very far from being the case ; 
the production of disease is a mere accident from the 
Trypanosome's point of view, an occurrence of fatal 
import for itself as well as the host should the latter 
die! 

Although only a few of the pathogenic species have 
been mentioned, all of them together are a very small 
fraction of the total number of Trypanosomes and their 
allies that are known. They occur in the blood of fishes, 
reptiles, amphibia, birds and,mammals ; in the vital fluids 
of molluscs, in the alimentary canal of insects and other 
invertebrates. 

By cultural methods it has been found that normal 
English cattle have Trypanosomes in their blood, and 
Bruce first found that even the species that cause disease 
in domestic animals lives harmlessly in the indigenous 
wild animals. Dr. Duke has shown that the " Situtunga " 
antelope {Tragelaphus spekei) carries in its blood the 
deadly Trypanosome gambiense without any harm to itself. 
It must be remembered that Trypanosomes are not like 
the bacteria such as that of anthrax, which form highly 
resistent spores, and by the death of their host and its 
disintegration are disseminated more widely in a condi- 
tion in which life may be maintained indefinitely. 

The position seems to be this. Many insects, for instance 

^ Stephens and Fantham, Proc. Royal Soc, Series B, 1910, No. 561, 
pp. 28-32. 

* J. W. Scott Macfie, Annals of Tropical Medicine and Parasitology, 
1913, August, vol. 7, No. 3a, pp. 339-56. 



16 NATURAL HISTORY OF SLEEPING SICKNESS 

the house fly, contain in the alimentary canal Flagellates 
of a type closely allied to Trypanosomes, which live a 
natural parasitic life in the fly only. 

When the ancestors of the present blood-suckers became 
addicted to this habit, probably a development of the 
habit of feeding on the fluid exuding from sores, it may 
well have happened that some of these internal parasites 
were inoculated into the blood of the animal. Those 
that survived may well have caused disease as a result 
of their vital activities ; if so, by the process of natural 
selection, those which soonest became adapted to the 
new conditions and no longer brought about a condition 
unfavourable to the host, on whose life they would now 
depend, would have most chance of surviving. 

This theory is supported by some very interesting 
work done by Fantham and Porter, who showed that 
Herpetomonas jaculum, a normal inhabitant of the gut 
of the " Water scorpion " {Nepa cinerea), when introduced 
into the peritoneal cavity of mice or even taken by them 
in food eventually finds its way into the blood and causes 
symptoms like those of " Kala-azar " in man, from which 
the mouse dies.^ But if the mouse had not died so 
quickly there might have been developed such immunity 
to the new substances circulating in its blood as the result 
of the vital activities of the Herpetomonas that friendly 
relations between the two would result and mammal 
and parasite would become"'mutually immune to each 
other, as appears to be the case with wild game and 
T. brucei. ^^ 

When man with his non-immune domestic animals 
comes into relation with this equilibrised system the 
equilibrium is disturbed ; the Trypanosome finds itself 
introduced into the circulation of hosts to which it is 
a novelty and *' disease " results. 

1 Fantham and Porter, Proc. Camb. Phil Soc, 1915, vol. 18, pp. 39-50, 
137-48. 



TRYPANOSOMES AND THEIR HOSTS 17 

But even man himself shows a gradual acquirement 
of immunity. In West Africa Sleeping Sickness is not 
generally so virulQnt as in the Uganda epidemic, and 
the disease has been known in that area for a very much 
longer time. The species of Trypanosome known as 
T. nigeriense causes only a mild form of disease which 
is very rarely fatal, so it would appear to be the species 
which has been longest in contact with man. On the 
other hand, T. rhodesiense is very much more virulent than 
any other human Trypanosome known to us, and it 
appears to have arisen as a sudden " mutation " from 
the animal -inhabiting species T. brucei. It is only ten 
years since this undesirable addition to the list of " human " 
Trypanosomes made its presence known to us by causing 
a disease previously unknown in that part, or at least 
unrecognized as distinct from malaria, 

Trypanosomes are transferred from one host to another 
by the agency of various invertebrates, which are as 
necessary for its existence as are the animals in whose 
blood they also live. 

In the blood they only multiply by fission, asexually 
or vegetatively ; but in the invertebrate host they go 
through a sexual form of reproduction. Development 
generally commences in the alimentary canal, whence the 
Trypanosomes find their way into the "salivary glands," 
so that they are inoculated into the new vertebrate host 
when the blood-sucker injects the irritating fluid secreted 
by those glands in order to produce a free flow of blood. 
The effect of this fluid is familiar to all who have been 
" bitten " by mosquitoes. Such an alternation of sexual 
with asexual methods of reproduction is called a "cycle" ; 
the complicated life history of the malaria parasite is a 
more familiar example. 

I think the fact that the sexual process takes place 
in the invertebrate host points to that being the original 
host for the Trypanosomes ; the life in the blood is as it 

3 



18 NATURAL HISTORY OF SLEEPING SICKNESS 

were an accident, and many close allies of Trypanosomes 
can do perfectly well without it. 

Trypanosomes of fishes are carried by leeches ^ ; of birds, 
by mosquitoes ; those of mammals by various blood- 
sucking insects. Thus, the rat Trypanosome is trans- 
mitted by the rat flea, the species causing " Surra " 
in animals by the large flies often called " Cleggs " 
{Tabanidce), and those causing " Nagana " in animals 
and Sleeping Sickness in man are carried by Tse-tse 
flies (Glossina). 

The Trypanosome of " Dourine " is particularly interest- 
ing, because it seems to have found that it can do without 
an intermediate insect host, and is transmitted directly 
from male to female animal, thus having severed all 
relations with the ancestral home ! 

It may be pointed out that there is a close analogy 
shown by Spirochaetal diseases of man, some of which 
are carried by an intermediate host while others are not ; 
the pathology of the two classes also shows much in 
common, which is not surprising, considering how closely 
allied are Trypanosomes and Spirochsetes. 

Lastly, the very interesting species which causes in- 
flammation of the thyroid gland with fever in Brazil, is 
carried by an insect {Conorhinus) of the order Hemiptera 
or " bugs," an order which numbers extremely few 
blood-suckers among its ranks, although all are adapted 
for obtaining food by suction. Darwin made special 
mention of this bug in his journal, and remarks that 
" one feast kept it fat during four whole months." ^ 

The Tse-tse fUes will now be dealt with more fully, 
but in this chapter I will only give a general account, 
reserving a full account of the natural history of Olosaina 
palpalis for another chapter. 

' See Miss M. Robertson's paper in Phii. Trans. Royal Soc, 1911, 
Series B, vol. 202, pp. 29-50. 

* Voyage round the World, edition 1890, p. 316. 



TSE-TSE FLIES 19 

Some sixteen species exist, which are entilrey 
Ethiopian in their distribution ; for though one species 
{tachinoides) is found in the south-west corner of Arabia, 
that area is faunistically part of the Ethiopian region. 
Tse-tse do not occur in Africa north of the Sahara nor 
south of St. Lucia Bay in Zululand. It is remarkably 
interesting, therefore, that fossil flies have been found 
in Colorado referable to this group, ^ and it has been 
suggested by Osborn that they were responsible at least 
in part for the extinction of many of the large mammals 
which abounded in Cainozoic times and by their 
migrations came into contact with blood-sucking flies to 
which, and their associated flagellates, they had not yet 
become habituated. ^ 

The first Tse-tse which I wish to mention particularly 
is Glossina morsitans, known to travellers in Africa as 
"The Fly," or, collectively, as "Fly." According to 
Austen ^ the exact origin of the name is uncertain ; it 
is believed to be a corruption of " Nsi-Nsi," said to be 
the name given to blood-sucking flies by natives of some 
parts of Africa. A passage in the Old Testament * possibly 
refers to Glossina, although it may also apply to other 
flies with the same habits : " And it shall come to pass 
in that day, that the Lord shall hiss for the fly that is in 
the uttermost part of the rivers of Egypt, and they shall 
come, and shall rest all of them in the desolate valleys, 
and in the holes of the rocks, and upon all thorns, and 
upon all bushes." 

The early African travellers of the middle of the nine- 
teenth century were, naturally, much impressed by the 
fly which was so well known to the natives for inflicting 
a " poisonous bite " upon their cattle. 

* Cockerell, Proc. of the United States National Museum, vol. liv. 1918, 
p. 308. 

* Letter from Professor Cockerell in Nature, 1919, June 5, vol. ciii. 
p. 265. « Monograph on the Tse-tse Flies, 1908, p. 32. 

* Isaiah, chapter vii. verses 18, 19. 



20 NATURAL HISTORY OF SLEEPING SICKNESS 

Thus Gordon Gumming in 1850 wrote as follows :i 
" When under the mountains on the south bank of the 
Limpopo river I met with this famous fly whose bite is 
certain death to oxen and horses. This fly is similar to 
the fly in Scotland called ' Kleg,' but a little smaller. 
They are very quick and active, and storm a horse like 
a swarm of bees, alighting on him in hundreds and 
drinking his blood. The animal thus bitten pines away 
and dies at periods varying from a week to three months." 

And again : " The next day one of my steeds died of 
Tse-tse. He had been bitten under the mountain range 
lying to the south of this fountain. The head and body 
of the poor animal swelled up in a most distressing 
manner before he died. His eyes were so swollen that 
he could not see, and in darkness he neighed for his com- 
rades who stood feeding beside him." 

Again, Livingstone in 1857 wrote as follows : ^ " The 
peculiar buzz when once heard can never be forgotten 
by the traveller, for it is well known that the bite of 
this poisonous insect is certain death to ox, horse or dog. 
In this journey we lost forty-three oxen by its bite. 
We watched the animals carefully, and believe that not 
a score of flies were ever upon them. 

" A most remarkable feature is the perfect harmlessness 
of the bite to man and wild animals." The italics are 
mine, to emphasize that the scientific mind of the great 
explorer had noticed this pregnant fact, although the full 
significance was not made plain until Bruce's work was 
published. ** We never experienced the slightest injury 
from them ourselves, although we lived two months in 
their habitat, which was in this case as sharply defined 
as in many others ; for the south bank of the river was 
infested by them, and the north bank, where our cattle 

^ Five Years of a Huntefa Life in the Far Interior oj South Africa, 
vol. ii. p. 210, etc. 

* Missionary Travels and Researches in South Africa, p. 79, etc. 



LIVINGSTONE'S ACCOUNT OF THE TSE-TSE 21 

were placed, only fifty yards distant, contained not a 
single specimen. This was the more remarkable as we 
often saw natives carrying over raw meat to the opposite 
bank, with many Tse-tses settled upon it." 

This account makes clear one of the most remarkable 
points in the natural history of this species of Glossina, 
namely, the very sharply marked areas which it inhabits ; 
this must depend upon the presence or absence of certain 
factors in its environment, but has not yet been thoroughly 
explained. 

After noting the symptoms of "fly disease " Livingstone 
continues : " These symptoms seem to indicate a poison 
in the blood, the germ of which enters when the proboscis 
is inserted to draw blood. The poison germ, contained 
in a bulb at the root of the proboscis, seems capable, although 
very minute in quantity, of reproducing itself." The words 
which I have put in italics were written by Livingstone 
about fifty years before the discovery of the Trypanosome 
by Bruce, and some years before the first discovery of 
micro-organisms of disease by Louis Pasteur ! ^ 

The genus Glossina was founded in 1830, when Wiede- 
mann described a new species of fly from Sierra Leone, 
and in the same year another species was described from 
the Congo by Robineau-Desvoidy : this is the one which 
is now known as Glossina palpalis. It is interesting 
that the first scientific description of a Tse-tse was not 
that of the one so long known to natives in South 
Africa ; this was not named until 1850, when Gordon 
Cumming's travels made the fly well known in England. 

Glossina palpalis frequents forested and humid country, 
and is not found so far south as its more widely distri- 
buted relative morsitans. The great river courses and 
lake shores in the tropics furnish the shade and humidity 

1 In 1857 Pasteur first showed that fermentation was due to micro- 
organisms ; in 1865 he showed that silkworm disease was due to micro- 
organisms. In 1876 the first '• bacterium " (of anthrax) was isolated 
by Koch. 



22 NATURAL HISTORY OF SLEEPING SICKNESS 

that it requires, hence the Congo basin, the upper Nile, 
and the shores of Lake Victoria abound with it. 

Tse-tse flies are on the whole diurnal, though one or two 
species are known to bite at night ; but the traveller is 
safe from both morsitans and palpalis after dark. 

The life history of the Tse-tse flies is very remarkable, 
and almost unique among insects. No eggs are laid, but 
a single egg is hatched within the abdomen of the mother 
fly and the larva, a white grub, is fed by the secretion of 
special glands. When the larva is full grown the mother 
fly seeks a suitable spot and the larva is extruded. It is 
a very active little creature, and crawls about seeking 
for a spot where it can burrow into the soil. It is helped 
to do this by two curious bosses at the posterior end of 
the body which are of hard chitin and give the larva a 
firm purchase when it begins to burrow. As soon as 
it has buried itself its skin hardens and it becomes a dark 
brown oval pupa with the two bosses at the posterior 
end which were seen in the larva, and differ in shape 
according to the species of fly. 

After a period of very varied duration the perfect fly 
emerges by cracking the pupa-case or " puparium " 
at one end and by means of an extrusible bladder on 
the front of its head works its way up through the soil 
covering it and creeps up a stem in a great hurry to let 
the wings hang down and expand before they have hard- 
ened. I have seen many palpalis thus emerge from the 
ground, and' they always give the impression that it is 
a matter of the utmost importance that they should lose 
no time ! 

Let us now glance at the development of our knowledge of 
Tse-tse flies and disease. It was quite clear to the earliest 
travellers in South Africa that *' The Ely," as Glossina 
morsitans was called, was a cause of the fatal disease of 
cattle and horses to which allusions have been made. 

Sir David Bruce in 1894 was able to report that the 



NAGANA AND SLEEPING SICKNESS 23 

actual cause of the disease ** Nagana " was a Trypanosome 
which was named brucei after its discoverer, and was taken 
up by a Tse-tse when it fed on the blood of an animal 
suffering from nagana. It was believed that the fly 
inoculated the Trypanosome into a fresh animal when it 
fed again in the same manner that a vaccinator introduces 
the lymph on the point of his lancet, that is to say, by 
direct inoculation. Thus in the case of Nagana we 
have started with the carrier of the disease and found 
the germ which it carried. 

When the problem of Sleeping Sickness became so 
acute in Uganda, the Royal Society sent out a Commission 
in investigate the disease, and the members arrived in 
Uganda in July 1902. But the first step towards the 
elucidation had already been made in West Africa. In 
1901 an Englishman in charge of a steamer on the Gambia 
river was admitted to hospital at Bathurst for " fever," 
and Dr. Forde found in his blood peculiar organisms 
whose nature was unknown to him. The patient was 
sent to Liverpool, and Dr. Dutton recognized the new 
organism to be a Trypanosome : the patient eventually 
died at the commencement of 1903. 

In 1902 Drs. Dutton and Todd found Trypanosomes 
in the blood of several West African negroes suffering 
from the early stages of what we now know to be Sleeping 
Sickness, but in those days the condition had not been 
recognized as connected with that well known disease. 
This early stage of fever now came to be known as 
" Trypanosome fever," or " Trypanosomiasis," and in 
March 1903 Dr. Baker found the Trypanosome in a 
case in Uganda, ^ though he did not recognize the full 
importance of this fact. The next development was the 
finding by Dr. Castellani of Trypanosomes in the cerebro- 
spinal fluid of a case of Sleeping Sickness in April 1903,^ 

» British Medical Journal, 1903, May 30th, p. 1254. 
* Proc. Roy. Soc, 1903, vol. Ixxi. pp. 501-8. 



24 NATURAL HISTORY OF SLEEPING SICKNESS 

and afterwards by Bruce and Nabarro in every case of 
Sleeping Sickness examined. Thus was made clear the 
fact that *' Trypanosome fever " is the early stage of 
the fatal disease, and the next step was to find out how 
the disease was transmitted. 

At this step a comparison of what was known about 
Nagana with what has been found out about Trypano- 
somiasis aids in the understanding of further developments. 
In the former case investigation commenced with strong 
presumptive evidence that a Tse-tse fly was the agent 
through which the disease was acquired ; in the latter 
case the germ was discovered and it became necessary 
to ascertain how it was transmitted. Since Nagana had 
been proved to be due to a Trypanosome carried by the 
blood-sucking fly Glossina morsitans, and Sleeping Sickness 
had now been shown to be due to another species of 
Trypanosome, evidence pointed to a blood-sucking fly 
as the carrier of this new species Trypanosoma gambiense, 
and requests were made to officials in the Sleeping Sick- 
ness area.s fo send specimens of all biting flies in the 
neighbourhood to the laboratory in Entebbe. It very 
soon became clear that one fly was found throughout 
the areas being ravaged by the disease, that is the shaded 
margins of the great lakes and rivers ; this fly was 
Glossina palpalis. Accordingly experiments were made 
to test whether the fly can be the carrier, and specimens 
captured on the shores of the lake were fed upon monkeys 
whose blood was examined daily, the procedure being 
the same as in Bruce's classical work on Nagana. Con- 
clusive proof was obtained when the Trypanosome was 
found in the blood of the monkeys, and the discovery 
was announced by the Commission in 1903.^ Further 
proof was obtained by feeding bred flies on monkeys 
which had been already infected by wild flies, and then 
making them feed upon another monkey ; the second 
^ Reports of the Sleeping Sickness Commission, No. IV, pp. 5G-65. 





FLY BEACH ON DAMBA ISLE. 

A favourite breeding ground is under tlie bushes at the gap on the right. 

^V f'er)iiissioit of the Royal Society and the Controller, H.M. Stationery Ofice. 




'^r^^ 
<^,~ yW' 




FLY BEACH ON BUGALLA ISLE. 
By permission of the Royal Society and the Controller, H.M. Stationery Office. 



To face p. J4. 



LIFE CYCLE OF TRYPANOSOMES 



25 



monkey in a proportion of cases also showed the Trypano- 
some in its blood. Control experiments showed that a 
freshly hatched fly contains no Trypanosomes, so that 
those in the above experiments must have acquired them 
from the first monkeys fed upon. 

The two diseases Nagana and Sleeping Sickness are 
thus entirely parallel, as is shown by the following table : 



Diseaso. 


Subject. Cause. 


Natural Host. 


Carrier. 


Nagana 

Sleeping 
Sickness 


Domestic 
animals 

Man 


Trypanosoma 
brucei 

Trypanosoma 
gamhiense 


Big Game 

The antelope 

Tragelaphus 

S2iekei 


Glossina 
morsitans 

Glossina 
palpalis 



It has been said that the transmission of the Trypano- 
some of Nagana was believed to be entirely mechanical, 
and for some years this was also thought to be the case 
with T. gambiense. With further knowledge, however, 
it became clear that there was a period after the fly 
had fed during which the Trypanosome could not be 
transmitted to a fresh animal. It had previously been 
supposed that this was because the Trypanosome was no 
longer alive in the fly, but KJeine, working in German 
East Africa, showed in 1908 that the non-infectivity of 
the fly after a few days did not mean the death of the 
Trypanosome, but that it was going through a cycle of 
development in the alimentary canal of the fly, and was 
not in an infective condition. For when the develop- 
ment was complete Kleine found that the fly could 
convey the disease fifty days after it had acquired the 
Trypanosome. These most important results were fully 
confirmed in Uganda in 1909 ^ and it was found that the 
time required for the cycle of development in tha fly 

* Reports of the Sleeping Sickness Commission, vol. x, p. 46, etc. ; 
vol. xi. p. 12, etc. 



26 NATURAL HISTORY OF SLEEPING SICKNESS 

varied, from eighteen to forty-five days, after which 
time a fly will remain infective and able to introduce 
the Trypanosome into every animal it bites for as long 
as seventy-five days ! 

The complete life cycle of the Trypanosome in the fly 
was worked out fully in Uganda by Miss Robertson 
in 1913.^ The Trypanosome multiplies in the gut of the 
fly, but the forms of m^ultiplication are not those which 
will live in the blood stream of the vertebrate host, and 
a somewhat different form is developed which finds its 
way into the " salivary " glands of the fly and is 
injected with the irritant secretion of the gland which 
presumably is intended to produce a free flow of blood 
in the site of puncture. We have now arrived at the 
most important fact that when once it has acquired 
the Trypanosome the Tse-tse fly can infect for the rest 
of its life. 

We must now consider the relations between Tse-tse, 
Trypanosome, and the " alternative hosts " of the latter 
from which the fly acquires it. 

It was known from Bruce 's researches on Nagana ^ 
that Trypanosoma brucei is a natural and harmless inhabi- 
tant of the blood of various species of big game in the 
" fly areas," and as soon as Sleeping Sickness was 
proved to be due to another Trypanosome, efforts were 
made to discover its natural host or reservoir. The 
Commission in Uganda made a series of experiments 
with the blood of such animals and birds that, inhabiting 
the lake shore, might be justly suspected of harbouring 
the trypanosome, but with negative results. One impor- 
tant species of antelope, however, was not at this time 
(1908-10) examined. The next step was to mfect captive 
antelope and native cattle by feeding upon them flies 

^ Reports of the Sleeping Sickness Commission, No. XIII, p. 119, etc. 
- ApjDendix to Further Report on Tse-tse Fly Disease or Nuga7ia in 
Zululand, 1903, p. 8. London, Harrison & Sons. 



RESERVOIRS OF TRYPANOSOMES 27 

caught in the Sleeping Sickness area, and it was found 
that this could be readily done ; waterbuck, bushbuck 
and reedbuck in captivity could all be made reservoirs 
of the Trypanosome without any harm to themselves, 
and could continue to infect bred flies fed upon them for 
more than twelve months after they had been artificially 
infected.'^ Finally, in March 1912, Dr. Duke announced 
that the antelope known to the natives as " Enjobe " 
was a natural reservoir of Trypanosoma gambiense, and 
the chain was thus completed. ^ 

It had seemed for some time probable that there must 
be a natural host, although it had not been found. Four 
years and a half after the natives had been removed from 
the islands the fly there was still infective, and it was 
impossible to suppose, that the same flies were still alive 
that had been the cause of the epidemic. With one 
exception the animals and birds and reptiles within 
reach of the fly had been sufficiently examined to make 
it almost certain that they were not incriminated, and 
the one large antelope living on the islands was yet to be 
excluded. Accordingly, in the latter part of 1911 Dr. 
Duke came over to my camp on Damba Island to shoot 
and investigate the very abundant " Enjobe " there. 
This antelope, the Situtunga {Tragelaphus speJcei), lives in 
most intimate association with the fly among the shaded 
forests at the water side. 

A number were shot and their blood was injected 
into monkeys, one of which, injected on November 5th 
and 6th, showed Trypanosomes in its blood on the 18th. 
It was taken to the laboratory on the mainland and the 
nature of the Trypanosome investigated in every possible 
way, and Dr. Duke considered that there was no doubt 
that he had at last found the source from which the 



* Reports of the Sleeping Sickness Commission, No. XI, p. 71, etc. 
^ Ibid. No. XII, p. 117 et seq. See also article by Duke in BiHtish 
Medical Journal, 1914, February 7th. 



28 NATURAL HISTORY OF SLEEPING SICKNESS 

flies on the island acquired the cause of Sleeping 
Sickness. 

This discovery made the question of the return of the 
natives to the lake shore a far more difficult one than 
was anticipated when they were removed during the 
height of the epidemic. It was then thought that as the 
fly was merely a mechanical carrier of the Trypanosome, 
an interval during which all known sources of infection 
(the natives) were kept away from the fly would allow 
the disease to die out, and when the life of the infected 
flies had come to an end, the natives who were free from 
Trypanosomes could return without danger. But now 
that it is known that there is a " vicious circle," the 
fly acquiring the Trypanosome from the antelope and 
in turn inoculating it into fresh animals, the islands and 
mainland shore of the lake are still dangerous. It is 
true that some consider that it is possible that the 
Trypanosome has been for so long away from man's 
blood that it may no longer be pathogenic to him, 
but against this is the fact that as a result of living on 
the islands with me in 1911-12 three of my native 
employees were found to be infected when I examined 
them before returning to the islands in 1914, and one at 
least is reported to have died. 

So far as we know at present, the fly would be harmless 
without the antelope and the antelope without the fly, 
and to eliminate the disease from the most fertile and 
beautiful part of Uganda these two must be kept apart ; 
that is to say, one of them must be exterminated. 

In 1914 I obtained most interesting confirmation of 
Dr. Duke's results. The Island of Nsadzi, lying opposite 
to Entebbe and south of it, was well populated in the old 
days, and there was very little refuge for Enjobe there ; 
I was told by my canoe-men that the antelope was not 
to be found on the island in those days. In 1911 the 
flies on Nsadzi were tested and were found to be free 



THE SITUTUNGA AND SLEEPING SICKNESS 29 

from infection, for as many as 5,765 failed to cause infec- 
tion in a monkey. In 1914, however, I frequently saw 
footprints of Enjobe on the island, which had presumably 
swum across the narrow channel between Nsadzi and the 
large isle Kome to the east where Enjobe abound. The 
flies were again tested and found to be infected, for after 
2,076 had fed upon a monkey it showed the Trypanosome 
in its blood. ^ Less than half the number of flies that 
did not produce an infection in 1911 produced an infec- 
tion in 1914, and this is associated with the arrival of 
the buck in the continued absence of the population. 

It seems hardly possible to entertain the idea of de- 
stroying the Enjobe, since when hard pressed it takes 
refuge in dense papyrus swamps, and even if it could once 
be eliminated from the islands would soon find its way 
back by swimming from the mainland, and would resume 
its former relations with the native. Is it, then, possible 
to eliminate the fly ? 

On this question I shall have something to say in 
the chapter devoted to the natural history of Glossina 
palpalis. 

^ Reports of the Sleeping Sickness Commission, No. xvii, 1919, p. 71-74. 



CHAPTER III 

THE NATURAL HISTORY OF GLOSSINA 
PALPALIS 

This species is pre-eminently a frequenter of the shady 
forests on the shore of the lake, where it may be found 
in great abundance. 

The method of estimating its numbers is to set trained 
natives to catch the flies with small nets from o£E the 
herbage or rocks on which they alight, or from their 
own clothing when the flies come to feed. At the end of 
half an hour the boys are whistled in and the catch 
counted, but, for reasons which will be given later, 
only the males are used. An average figure is obtained 
representing the number caught per boy per hour, 
commonly alluded to as the " male-boy-hour " figure, 
by means of which one locality can be compared with 
another. The highest figure I have yet recorded was 
obtained in 1919 on the north coast of the west of Kome 
Isle : four boys working for half an hour obtained the 
average of 125 male flies per boy per hour. If it be 
considered that each fly is caught in a net, from which 
it has to be taken out by hand and put into a bottle, 
and that besides the males there were at least a quarter 
as many females caught at the same time, it must be 
admitted that the fly can be very plentiful ! 

One of the first things to be realized is that the number 
of flies at a locality has little relation to the frequency 
with which one is bitten, and therefore an impression 

30 




ON DAMBA ISLE. 
Not a good fly shore, as it was too marshy for a breeding ground. 




A 1 l.V l;uV (JAKOBO) Ai WUKR. 

The white net in his right hand scarcely shows against his white clothes. He was found to 
be infected with T. Hambiense in 1914. 

To face p. 30. 



wmmmt^mmi^-,Ti, 



PROPORTION OF SEXES 



81 



derived from a large number of bites gives a very erroneous 
estimate. This fact has arisen from Fiske's investigations 
into the reasons for the very varying proportions of the 
sexes at different localities. 

It has been found that the females are much less inquisi- 
tive than the males, and do not come to man in any great 
numbers unless wishing to feed, whereas the male roams 
about and investigates any new object without necessarily 
being hungry. The percentage of females is therefore 
an indication of the hunger of the flies. If, however, 
a prolonged catch is made in one spot, the percentage of 
females rises, because the more inquisitive males are 
first caught ; the number of females per boy per hour, 
however, remains fairly constant, since only the hungry 
individuals are taken. 

An experiment such as the following illustrates this 
point clearly. Flies were caught continuously at one 
point on the small island of Tavu on January 13-16, 1914, 
from early morning until the afternoon, and it is clear 
that the number of males was soon affected, while the 
catch of females remained constant. The percentage of 
females, however, rose, owing to the males being caught 
ofi ; not in this case because there were more females 
eager to feed. 



Date. 


Time. 


Total 
Catch. 


Males per 
Boy-Hour. 


Females 
per Boy- 
Hour. 


Percentage 

of 

Females. 


Jan. 15, 1914 


7.45-8.45 


473 


62.5 


7.5 


10.7 


»» >• 


9-10 


303 


36. 7 


4.3 


10.5 


»» >» 


10.15-11.15 


235 


23.5 


6.5 


21.7 


J» M 


11.30-12.30 


216 


20.3 


6.8 


25.0 


>> >» 


1.30-2.30 


222 


20.3 


7.5 


27.0 


Jan. 16, 1914 


7.4.5-8.45 


275 


33.0 


5.7 


14.7 


>> >> 


1.25-2.25 


241 


21.0 


11.4 


35.2 


>> >> 


2.45-3.45 


128 


9.8 


7.1 


42.0 



The relation between the percentage of female flies in a 



32 NATURAL HISTORY OF GLOSSINA PALPALIS 

catch and the hunger of the flies was borne out by the 
behaviour of flies on different islands visited by Fiske 
and myself in 1914. (See Chapter VI.) Certain islands, 
notably Kimmi and Yempata, were remarkable for the 
avidity with which the flies bit ; on Kimmi they even 
flew out to the canoe before it reached the shore. On 
both these isles the percentage of females was higher 
than usual ; on Kimmi it averaged 53 per cent., on 
Yempata 37 per cent. 

The curiosity and spirit of investigation of the male 
fly was shown by a little experiment on Tavu Island. 
I noted that during the passage through some thick 
Kinsambwe bushes many leaves became reversed so 
as to show the silvery under surface. Male Tse-tse 
often settled on them as if attracted by the novelty. 
I therefore spent some time catching every fly that settled 
on my white net, held out conspicuously, and in one hour 
thus caught twenty-six males, but only six females. 
I then caught from off my clothes those flies that had 
settled and lowered the proboscis intending to feed ; 
there were ten females to eight males. Male flies may 
very often be seen which seem to have no desire to feed, 
but merely to rest in a conspicuous position, often on a 
rock hot with the sun ; possibly they are on the watch 
for females. There can be no doubt that they use their 
eyes in the search for food : it has long been known in 
the case of G. morsitans that a man on horseback or cycle 
moving will attract flies where none have been noticed 
while he was stationary. Palpalis would often alight on 
the canoe drawn up on the beach ; presumably the large 
black object was thought at first to be a hippopotamus ! 

The fact that the fly will often sit on a rock hot with 
the sun is of interest, seeing that they are apparently 
dependent upon shade, and are susceptible to variations 
in the humidity of the atmosphere. I am convinced, 
however, that so long as palpalis has a shady base it will 



ROAMING OF THE FLY 



88 



make long excursions from it, perhaps in search of food 
or breeding places, and may be found in places where 
there is practically no shade and where it could not abide 
permanently. Thus, the western end of Nsadzi Island 
consists of a high treeless grassy plateau sloping down 
steeply to a rocky shore along which is a scanty fringe 
of sparse bushes throwing very little shade over the bare 
rocks. Yet if one descends to the shore fly is met with, 
and one is immediately investigated. 

An experiment was made to test whether the fly does 
roam along this kind of coast. At one point there was 
a small copse about thirty yards square, furnishing ample 
shade to provide a base for the fly, and ten fly boys were 
set to catch flies continuously here on June 10, 1914. 



Time. 


Number of Flies 
Caught. 


Males pet 
Boy-Hour. 


Femalea 

per 
Boy-Hour. 


Percentage 




Male. 


Female. 




9-45-1115 

11-20-11-50 

12 -12-30 

12-30-1 

1-10-1-401 

1-45-2- 15 

2-15-2-45 


51 
16 
12 
16 

17 
9 


18 

24 

15 

6 

24 

17 


3-4 
3-2 
2-4 
3-2 

3-4 
1-8 


1-2 
4-8 
3 
1-2 

4-8 
3-4 


26 
60 

65-5 
27 

58-5 
65 




121 


104 


— 


— 


— 



The fact that the number of males caught per boy per 
hour was almost unaltered until the end shows that the 
121 flies could not have been in the copse at the com- 
mencement, but that a continual influx occurred. Had 
the flies all been there at first ten boys would soon have 
diminished the number. Also, after an interval spent 
in looking for pupae there was a decided increase in the 
total number of flies caught. 

1 One empty puparium found. 

4 



34 NATURAL HISTORY OF GLOSSINA PALPALIS 

It is of some importance, for reasons that will appear 
later, to know whether palpalis does roam out of the 
shade. There is no proof whatever that it wiU ever cross 
the open water from one island to another. The little 
islet Sanga, ofi the east end of Kome, has everything that 
the fly can want, but for some reason it is unable to 
establish itself there, and none can be found. Yet the 
adjacent shores of the larger Kome abound with fly, and 
it could very easily find its way across the few hundred 
yards of water to Sanga, yet it does not. 

Palpalis, like morsitans, is at times a great nuisance, 
for it will quietly sit on men's backs and thus be carried 
a long way. Indeed, I have sometimes unwittingly taken 
them back to my tent, where they remained, and rudely 
bit me while having a bath ! On certain days, when it 
is somewhat overcast but the sun shines through thin 
clouds, they are perhaps at their worst, and are very 
eager to bite, and will cling to one for long distances. A 
very favourite trick is to alight on the under side of the 
brim of one's hat and to quietly sidle round until the first 
piece of skin free from hair is met with, when the proboscis 
is lowered from its sheath and a sharp prick is felt on one's 
temple. It is a curious fact that sometimes one is quite 
unaware of being bitten, and may suddenly hear the 
unmistakable heavy buzz of a bloated fly leaving after 
a heavy feed ; at other times the prick is felt so sharply 
that it might be produced by a needle. Presumably the 
difference depends upon whether the fine point of the 
proboscis finds a nerve end or not ! 

When a fly alights to feed it sidles about over the 
skin and appears to be feeling for a soft place : when it 
is satisfied the legs are slightly straddled out, and the 
proboscis lowered from its sheath into a vertical position, 
after which it gradually penetrates up to the bulb at its 
base. It is then withdrawn slightly and the body of the 
fly begins to swell with red blood. Almost at once the 



FOOD OF THE FLY 85 

excess of fluid is exuded as a bead at the posterior end of 
the body, so that the fly is enabled as it were to have a 
larger feed of corpuscles than if it were compelled to retain 
all the fluid part. After a full feed the abdomen becomes 
as large as a ripe red-currant, and the red blood shows 
through the distended skin ; the gorged insect flies heavily 
away to a neighbouring leaf and rests awhile to digest 
the meal ! 

On clear hot days, when a strong wind may be blowing, 
palpalis is not so eager to bite ; nor on any day during 
the hottest hours. But about 4 p.m. it is always ready 
again, and I have been bitten quite in the dusk of the 
late afternoon : at night, however, it is harmless, nor 
does it come to light as the big East African species 
brevipalpis is known to do. This habit of biting again 
more freely in the evening is of interest, for it is at this 
time that the Situtunga antelope, which is a source of 
food, comes out from the dense forests and wanders 
along the edge browsing on the bushes, where it meets 
palpalis. 

The question of the food of Tse-tse flies is of the highest 
importance, and was one of those set me by the Tropical 
Diseases Committee of the Royal Society when I first 
went out in 1910. In the case of morsitans certain ob- 
servers, notably the late F. C. Selous, held that the blood 
of buffaloes was essential to it, and that it died out or 
migrated if none was available. Few observations had 
been made on Glossina in a state of nature, but from 
an examination of the blood taken from the stomachs 
of wild flies the Commission in Uganda in 1910 ^ had 
deduced that " the blood in the majority of the flies had 
been obtained from birds or reptiles, and of these the 
reptilian blood was twice as frequent as the blood of birds." 

It must however be confessed that the method employed 

^ Report XI of the Sleeping Sickness Commission, 1911, p. 112, 
etc. 



36 NATURAL HISTORY OF GLOSSINA PALPALIS 

of distinguishing between avian and reptilian blood was 
crude and open to a wide margin of error, 

I repeated this work with a greater number of flies and 
at greater length, and using as standards such sources 
of food as the flies might meet with, viz. cormorant, croco- 
dile, Varanus, python, frog and lizard. 

At Jinja I had found that the proportion of mammalian 
to non-mammalian blood in over 12,000 wild flies was 
indicated by 

M : N :: 31-5 : 68-5. 

On Damba Island the proportions in over 6,000 flies were 

M : N : : 21 : 79. 

Now in both these places antelope's blood was readily 
obtainable, for Situtunga abounded on Damba and bush- 
buck were constantly seen in the fly area at Jinja ; hippo- 
potami were of course available at both localities. In 
1914 further work was done and blood was examined 
from flies taken on islands where there were no Situtunga, 
and others such as Kome, where Situtunga abounded. 

In flies from five small islands not inhabited by Situ- 
tunga the proportions of mammalian to non-mammalian 
blood were : 

M : N : : 4 : 96. 

On two isles inhabited by the buck the figures were : 

M : N : : 25 : 75. 

Now on all islands hippopotamus blood is obtainable ; 
indeed, on those of the first group it was the only possible 
mammalian blood, and accounts for the 4 per cent, of 
cases. 

But even where Situtunga are present only about one 
quarter of the food is obtained from them, and it appears 
that Glossina palpalis much prefers non-mammalian 
blood. 



ANIMALS FED UPON 



37 



The question then arises, does this come from birds 
or reptiles ? In 1911-12 careful measurements were 
made in forty-six cases, that is, from blood taken from 
flies that had fed recently enough to allow the corpuscles 
to be measured unaltered by digestion. 

In each case fifty corpuscles were traced with the camera 
lucida, and the average measurements obtained for com- 
parison with known types. Although in some cases a 
given specimen was with difficulty allotted to any one 
type, the following result was arrived at : 



Source. Percentage. 


Actual 
Number. 


Source. 


Percentage. 


Actual 
Number. 


Avian 
Reptilian 


4-3 
95-7 


V 

4^^ 


Lizards 

Crocodile 

Tortoise 


56-8 

40-9 

2-3 


25 

18 

1 


— 100 46 

i 


— 


100 \ 44 

j 



In two cases birds appear to have been the source. These 
would in all probability have been cormorants or darters, 
which so often sit on a branch at the edge of the water 
with the wings spread open ; but the herons and ibis which 
frequent the shore may also be bitten. 

Nearly 57 per cent, of the blood derived from reptiles 
seems to have come from lizards, probably entirely from 
the great monitor or Varanus, but measurements of the 
corpuscles from it and one of the common small brown 
lizards did not allow any distinction to be drawn. 

There is no possible doubt that Varanus is a most 
important source of food. I have several times seen one 
slowly sculling along the surface of the water near the 
shore, with the top of its head black with Glossina which 
were evidently so troublesome that at intervals the 
reptile submerged its head beneath the surface, only 



38 NATURAL HISTORY OF GLOSSINA PALPALIS 

to be reattacked the moment its head was raised. On 
one occasion when sitting on the beach of Damba I saw 
a Varanus come out from the forest and walk slowly 
past me. Tse-tse were around me in considerable num- 
bers, but the Varanus was evidently equally attractive, for 
several went to it and began to feed, as was evidenced 
by the repeated movements it made to scratch them off 
with its hind legs. 

Crocodiles are also an extremely important source of 
food, and their habits favour this, for like Varanus they 
often lie for long periods at the water's edge. Measurements 
of the blood corpuscles in wild flies seemed to indicate 
that nearly 41 per cent, of the reptilian blood is from 
this source. It appears at first sight rather remarkable 
that the horny plates should prove no impediment to 
the proboscis of the fly ; yet Fiske and I on Kimmi in 
1914 watched closely for half an hour a small crocodile 
which the natives had caught and was tethered near the 
water, and between 8-35-9-45 a.m. forty flies had fed 
fully ! This figure did not include those that were 
disturbed and did not feed to repletion. 

The sites chosen by the fly were carefully noted in each 
case save two, and are indicated below : 



Eyelid 






. 12 


Hind leg . . 






9 


Neck 






6 


Flank 






2 


Fore leg . . 






2 


Nose 






2 


Shoulder . . 








Nostril 








Angle of mouth . 








Hind foot . . 








Back 









38 



It is seen that the fly was even able to penetrate through 
the back ! 



ANIMALS FED UPON 39 

On Ngamba Isle I was able to see two flies upon a large 
crocodile that was resting among the bushes and had 
not run away at my approach ; one of them had certainly 
fed. 

In a single case out of the forty-four in which the 
blood in wild flies was recognizable the corpuscles agreed 
well with those of a tortoise. Glossina seems to recog- 
nize even this as a source of food, for I saw a tortoise 
one day with a fly on its back making vigorous attempts 
to find a way for its proboscis through the shell. But 
though a crocodile's plates are not insuperable, I fancy 
that the carapace of a tortoise is proof, and the fly would 
have to penetrate a leg or the neck. 

No example of blood that could be attributed to snakes 
was found among the forty-four cases, but the python 
certainly must be counted as a source of food. On 
Kimmi in 1914 I came upon a small specimen lying among 
marshy grass close to the water, and two flies were on 
it, one of which had the swollen red body indicative of 
a good feed. Other snakes also seem to be attractive, 
for on Ngamba in 1914 I saw a black species lying on 
rocks about to shed its skin and in the usual lethargic 
condition. Two male flies were upon it and were 
obviously attracted by it, though they did not seem 
desirous of feeding. 

Lastly, the lung fish, Protopterus (the " Mamba "), 
has been suggested as a source of food, though I do not 
understand how it could serve as such, seeing that it only 
appears at the surface of the water for a brief interval 
to obtain a supply of air. Examination of its blood showed 
that it is a physical impossibility for the fly to feed upon 
it, for the corpuscles are so enormous that only one at 
a time could pass up the proboscis, which would require 
a very great effort of suction on the part of the fly ! 

The figures that have been given represent the result 
of examination of many thousands of wild flies. For 



40 NATURAL HISTORY OF GLOSSINA PALPALIS 

out of a large number caught on a given day only a few 
would contain fresh blood, and in these cases a proportion 
would be mammalian blood. In the other cases many 
would be merely recognizable as nucleated non-mammalian 
blood, and in only a very small proportion would the 
corpuscles be sufficiently unaltered to allow of measure- 
ments being taken. 

During this work note was taken of the presence or 
absence of Trypanosomes in the gut of the fly, and in the 
proboscis. Certain Trypanosomes (e.g. T. vivax, which 
kills goats very quickly) only develop in part of the 
proboscis and are not found in the gut ; but others, such 
as gambiense, may be found in both. 

Of 600 flies examined at Jinja, 11 per cent, contained 
Trypanosomes in the gut ; of 695 on Damba, 34 per 
cent, had Trypanosomes ; and on Bugalla 1,000 flies 
showed Trypanosomes in the gut in 1*7 per cent, of the 
total. Out of 638 cases in which the proboscis was 
examined on Bugalla, 14 had Trypanosomes in the 
proboscis alone ; i.e. 2*2 per cent, of the wild flies appear 
to be infected with Trypanosoma vivax. ^ 

It must not be supposed that all the Trypanosomes 
found in wild flies are gambiense : some are devived from 
the crocodile {T. grayi), and so far as is known are harm- 
less. 

Besides Trypanosomes bacilli are often found in count- 
less numbers in the gut of the fly, but in a different part. 
Nevertheless there appears to be some inverse relation 
between the two, for out of six hundred flies at Jinja, 
in only 3' 4 per cent, of flies containing bacilli were 
Trypanosomes also found, and in only 61 per cent, of 
flies containing Trypanosomes were bacilli found. 
Bacilli were present in 19-3 per cent, and Trypanosomes 

^ Dr. Duke has shown that the Situtunga is a natural host of T. vivax 
as well as of T. gambiense. ReiJort No. XII of the Sleeping Sickness 
Commission, p. 122. 






o 



il 



< a 

3 



12. 



v^ 







,»o *t — o a- » r*-,* V 



u 


l<! 


CS 


^ 






2- 


a; 






:= J3 


5j 



J- •)*-*- o 



To face p. 40. 



BACILLI AND TRYPANOSOMES IN THE FLY 41 

in 11 per cent, of the wild flies. Thus there is marked 
incompatibility between the two. 

Since I have found bacilli in the gut of freshly hatched 
flies, and even in pupae, their presence in the fly may have 
something to do with the fact that only a few out of a 
batch of flies fed upon an infective animal at the same 
time will prove suitable hosts and will subsequently be 
found to contain Trypanosomes. It may be that the 
presence of bacilli in numbers is inimical to the Trypano- 
some, or merely that they are present in flies which for 
some other reason are physiologically unsuited to the 
development in them of the Trypanosome. It would 
be interesting to note the presence or absence of baciUi 
in flies which contain T. vivax only in the proboscis. 

One of the points set me to be investigated was whether 
palpalis can feed on anything except blood. I have not 
been able to obtain any evidence that vegetable juices 
are sucked up save that on Damba Isle I several times 
found grains of banana starch in preparations made from 
the gut of flies. I am inclined to think, however, that 
this was accidental contamination of the preparation, 
perhaps from a cloth used to wipe the slides, for it is 
difficult to see how such material as banana could be 
sucked up the narrow proboscis of Glossina. Small 
fragments of vegetable tissue were sometimes met with 
in preparations from the gut of a fly, but I am disposed 
to think that they had been sucked up in water, for 
pieces of alga were also found. 

Flies paid no attention to juicy papai fruit taken 
down to the shore, although I have seen a mosquito 
greedily feeding thereon. 

There seems more evidence that palpalis imbibes 
water, but though they have often been seen sitting on 
wet mud, no fly has ever been seen with its proboscis 
lowered into the water. 

Examination of the contents of the gut of many 



42 NATURAL HISTORY OF GLOSSINA PALPALIS 

hundreds of flies on Damba and Bugalla Islands, as well 
as at Jinja on the mainland, has shown various forms 
of algae and other low vegetable organisms that must 
have come from water ; and once a very minute ostracod 
crustacean, only about three times the length of a 
human red blood corpuscle, was found. Figures of 
these are given in my first and second reports. 

Experiments were made to see if flies lived longer when 
able to obtain juice from fruit than when starved, but 
access to fruit made no difference. The longest time for 
which a wild fly has been kept without food or with only 
fruit juices available is nine days ; a freshly hatched 
fly will live for eleven days. After a single feed of blood 
a fly lived for fifteen days (the longest period). This 
is a remarkably short period, and if it is so in natural 
conditions is rather surprising. Animals such as ticks 
appear to be able to live for months after a single feed of 
blood; the fly, however, is a more active creature, and 
lives at a higher rate. 

What is the natural length of life of palpalis ? This 
was one of the first things to be settled when I went 
out in 1910. For it was then not at all clear why the 
flies on the lake shore continued to be infective several 
years after the presumed sources oi~Trypanosoma gambiense 
(i.e. the natives) had been removed from reach of the fly. 
There were two possibilities — either the fly was acquiring 
infection from some wild animal, or the same flies were 
still alive on the shore that had been the cause of the 
epidemic some years before. It was not until 1911 that 
Duke showed what the reservoir of gambiense was, and I 
have showed that the fly probably does not live for more 
than one year. The drier months of the year cause a large 
falling off in numbers, so that a fly which has been living 
for some months probably succumbs when the trying 
period of diminished humidity comes at the beginning 
of the year. 



CHART II 



9/0 


A 


C7. 






Sept 






Ocd. 






/J^*-. 




ff^c. 






^/an 






/9'f 


76 




























1 




















76 


75 




"^ 


s 








































- 


- 


76 


74- 








N 


































TA 


7^ 










-^ 


^ 


















/ 


L_ 












73 


72 














•^ 


s 












/ 


V 












7Z 


7f 


















N 
















/ 




A 










- 


7/ 


TO 




















\ 


s 










/ 








\ 








ro 


63 
























-N. 








/ 








\ 










69 


68 


























V 


s, 


/ 










\ 








— 68 


67 




























( 






















67 


66 
















































— 


66 


66 
















































65 


6-t 












































V 




-.64. 


f' 












































— \ 






63 


6? 


















Tc'mjferctfUre 


























i?r. 


7-4 










































74 


7=^ 














































» 


- 


75 


7Z 
























^ 


^^ 








-^ 






r^ 


"p' 


n 




72 


7/ 




















^ 


V' 














S 


•^ 












7/ 


70 












,< 


-- 


-^ 
































~ 


70 


60 










^ 






































53 


Cd 






^ 












































6S 


ff 


















































.'/ 


to 


















fZ/'fj caught. 
peri>oy 
per hour 












) 


>~^ 












/O 


g 




























/ 








"~' 


> 




9 


fi 




— 1 


Ci; 




— 




s 




















/ 
















3 


7 














■ s 


\ 


















t 
















7 


6 


















N 


s 












/' 


















6 


>T 




















1 


<. 


^ 






/ 








\ 










5 


4 




























->l 


/ 




















4- 


■ 60 


















































Li? 


-W 






^ 






























/ 


\ 












S9 


^ 






\^ 






























1 




\ 










58 


57 








V 










firree/itaoe 










/ 








\ 








27 


"ifi 








\ 












f /ema/es 
'auyht 








1 












\ 






55 


i^ 










\ 














1 














> 




55 


H 










\ 










/ 


s 








y 


















— 


5-f- 


^i 












\ 






y 






■^ 


■^ 




/ 


















S3 


f? 












\ 


^ 


^ 












■v, 


r 
















~ 




S2 


S/ 




































^ 




1 






_ 


51 



INFLUENCE OF CLIMATE ON NUMBERS AND PROPORTIONS OF 

FLIES AT JINJA, ON MAINLAND. 
By permission of the Royal Society and the Controller, H.M. Stationery Office. 



To face p. 42 



DURATION OF LIFE 43 

A chart made at Jinja in 1910 (see Chart II) 
shows very clearly the direct relation between relative 
humidity of the atmosphere and the number of flies that 
could be caught. 

In order to estimate the length of life of the wild fly, 
the method adopted was one that had been used by 
Dr. Bagshawe to ascertain how far the fly would follow 
canoes or men. 

Large numbers of flies were captured, a portion of one 
leg was amputated through the middle of either femur or 
tibia (limbs may be lost at a joint naturally, but never 
in this way), and then the fly was liberated. By con- 
tinually catching flies at the same point day after day 
it could be ascertained for how long a marked fly had 
lived. 

Since a fly has six legs and each can be marked in two 
ways, twelve markings are possible : one method of marking 
was kept for the flies of each week. At Jinja, between 
July 27th and October 15, 1910, some eight thousand 
flies were so marked, and eight markings were used, an 
average of a thousand to each marking. 

Between August 3rd and February 11th, careful exami- 
nation was made of each fly caught by the boys, who 
worked every day for four or five hours. On January 
31st, 1911, a female fly was taken that had been marked 
on one of the days July 27 to August 2, 1910, and on 
December 29th a male was taken that had been marked 
on one of the days July 27 to August 2. This gives 
a period of life of at least 182 days for the female and 
149 days for -the male, but it is of course impossible to 
say for how long before the marking the flies had been 
alive : probably they were hatched fairly recently. 

On Bugalla Island in 1912 this experiment was repeated, 
and between March 18th and April 26th nine thousand 
flies were marked in six different ways. The last marked 
flies to be caught were noted on January 17, 1913 : two 



44 NATURAL HISTORY OF GLOSSINA PALPALIS 

males that had been marked between April 1st and 6th. 
This gives a minimum duration of life of 247-253 days 
for the male. A female fly caught again on August 17th 
had been marked between April 8th to 13th, so it had 
lived at least 126 to 131 days. This was not quite so 
long as the longest Jinja period (182 days). Thus it was 
established that palpalis can live for several months, but 
the probability is that it does not survive a second dry 
season. In both experiments the last flies were caught 
at a time when the relative humidity of the air was 
low. 

Both at Jinja in 1910 and on Bugalla in 1911-12 care- 
ful meteorological data were kept, and the influence of 
climatic conditions upon the total number of flies that 
were caught per boy per hour was found to be very 
interesting (see Chart III). 

In those days the male catch alone was not used as a 
means of estimation. 

The number of flies caught at Jinja on the mainland 
varied directly with the relative humidity of the atmosphere, 
which itself varied during the period from the beginning 
of August to the end of January from 63 per cent, to 
76 per cent, (see Chart II). 

On the other hand, on Bugalla Isle no such relationship 
could be made out, but here the relative humidity only 
varied from 77 per cent, to 72 per cent, during a continuous 
period of twelve months. On the mainland there was a 
very decided inverse relation between the number of 
flies caught and the temperature. In the hotter (and drier) 
months there were fewer flies. This did not seem to be 
so markedly the case on Bugalla, probably because the 
humidity of the atmosphere was so much more constant 
on the island that a higher temperature did not necessarily 
kill oflt the flies. 

In this fact may be the explanation of the occurrence 
of flies on Nsadzi at the west end, where there was so 



*) % > WW 

i- r-'--* ~* w W a J 







3 Q 



a r ;§ 



CJ 11 



O a; 






.r-T-T-'r 



a.?~ p: ?- SCrS S "J ^ f* :- ? <>■ "fi '~"? 1 + ~> " - 



To fa:e p. ^4. 



INFLUENCE OF CLIMATE 45 

little shade : the humidity of the island atmosphere 
saved them from the heat that might have been fatal 
on the mainland. 

Secondly, the hunger of females, as estimated by the 
numbers caught, is very dependent upon the temperature. 
Fiske proved to me in 1914 that the female percentage 
is not an indication of the actual numbers but of the 
hunger of the fly. Since the percentage figure varies 
inversely each month with the temperature, as is shown 
by the charts for Bugalla and Jinja, it follows that the 
hotter the month the less the fly is inclined to bite. 
Indeed, I have noticed on individual days that the fly 
bites less during the hottest hours, and less on a brilliant 
sunny day than when the sun's heat is tempered by thin 
cloud. 

A further effect of climate was noted on Bugalla, 
namely, upon the number of pupae that could be found 
each month (see Chart IV). 

At the end of every month the boys visited certain 
well known sites much liked by palpalis for its pupae, 
and an average figure was obtained called " pupae per 
boy " to indicate empirically the number found per 
month. It is obvious that the total number found at 
the end of each month must depend in part upon the 
number of female flies, which is indicated, at least as 
regards the number of hungry flies, by the *' female-boy- 
hour " figure for the month. 

If the " pupae-boy " figure be divided by the latter 
figure, the quotient may be used as a means of comparing 
from one month to another the rate of reproduction, 
bearing in mind that the times when the flies are hungriest 
will thus appear as months when the reproduction figure 
"pupae per female " is lowest. 

Thus, the average number of pupae found per boy in 
the given time at the end of February was 187-3 ; the 
average number of females caught per boy per hour during 



46 NATURAL HISTORY OF GLOSSINA PALPALIS 

187-3 
that month was 6-3. = 29*7, which is the " pupae 

D' o 

per female " figure for the month. 

If these figures are plotted out for the twelve months, 
it is seen that the curve thus formed is inverse to the curve 
of relative humidity. This may be a definite adaptation 
to enable Glossina to tide over the drier months, which 
are adverse to the adult fly. That is, during the drier 
months (of lessened humidity) more pupae are deposited, 
the pupa being resistant to a greater degree to adverse 
climatic influences than is the perfect fly. 

Experiments were performed to test the vitality of pupae 
exposed to various conditions of dampness or drought. 
Batches of pupae were submerged in water daily for difiPer- 
ent lengths of time, and it was found that daily submersion 
for twelve hours on twelve successive days only destroyed 
36 per cent, of the pupae, and that only 33 per cent, were 
destroyed by four submersions of twenty-four hours, 
with an interval between each of twelve hours. The 
effects of continuous submersion were tried, and it was 
found that a period of 108-120 hours is necessary to 
destroy all the pupae in a batch. 

Flotation on the surface can be borne for eight days, 
but ten days are fatal. 

Pupae were also put in a small wooden box covered 
with one inch of earth, and the box was sunk in the ground 
flush with the surrounding surface and left exposed 
to the sun during the hottest hours of the day. A single 
exposure up to six hours does not harm the pupae, but 
if uncovered by earth a single hour is fatal. The effect of 
repeated exposures on successive days was then tested : 
two hours daily for three days made very little difference 
to the pupae, but three hours daily for three days resulted 
in only 2 per cent, of flies emerging ; six hours daily for 
two days killed all. Lastly, alternate submersion and 
exposure are fatal ; although a single submersion of 



•a a 4 



O 




O M ^ 



a. CQ 






•siEiuaj jsd asdnj; 



To face p. 46, 



FLUCTUATIONS IN NUMBERS 47. 

twelve hours, or four hours exposure to sun have, alone, 
very little effect, if the pupae were submerged one night 
and exposed to sun next day only one per cent, developed 
into flies ! 

Besides variations in numbers of the fly due to climatic 
conditions, I found in 1914 interesting variations that 
were very puzzling. The small islands Bulago, Kimmi, 
Tavu and Ngamba were each visited weekly from the 
camp on Kome, and catches were made of flies at the 
same spots around the coast. 

It soon became obvious that the numbers of flies (as 
estimated by the number of males caught per boy per 
hour) on each of the four islands did not vary concurrently, 
and that variations did not affect the sexes in the same 
way on the same island (see Charts V and VI). 

On Bulago, for instance, on the south point and west 
shore the two sexes on the whole varied together, but 
on the shore of the north bay they varied inversely. 
In the forest of the north point the variations in number 
of the males were very great, while the number of females 
kept very constant. On Kimmi it was noted that the 
catches from two localities on the north and north-west 
shores of the island, taken together, varied inversely to 
the catches from the south and south-east shores, though 
this was less marked after the beginning of July. This 
must mean that at certain times the male flies found the 
north shore more congenial, whereas at others they 
congregated on the south side of the isle. 

By charting together the figures representing the 
average catch per boy per hour of males and females for 
each of the four islands, a curious and interesting point 
was brought to light. 

On the island where the number of males shows the 
greatest fluctuations the female figure shows least, and 
vice versa, and the same was found to hold good for 
individual localities on Bulago Island. On Tavu Island 



48 NATURAL HISTORY OF GLOSSINA PALPALIS 

the curve for male flies shows great variation, the female 
curve little, but on Kimmi the female curve is the 
greater variant and the male curve more constant. It 
may be that the supply of food on Tavu is so good that 
the females are well fed and do not come in any numbers 
to be caught by the fly boys, whereas on Kimmi the food 
supply is more erratic : it must be said, however, that 
there is no direct evidence for this. 

A very interesting relation was made out on Tavu 
between the number of flies caught at the weekly visits 
and the number of crocodiles seen when the island was 
circumnavigated in the canoe before a landing was made 
at each visit. There was a large flat topped rock on the 
east coast forming a little plateau that was always in use 
by crocodiles as a basking place ; the number on it 
varied from one to four, and others were seen in the water. 
On one visit as many as fifteen large crocodiles were 
seen on or about this small island, and on that day the 
number of flies was at the rate of ninety-three per boy 
per hour ! The lowest figure was fifty-six per boy- 
hour when only two crocodiles were seen. The accom- 
panying chart shows well the concurrent variation in 
numbers. It must be confessed that the explanation of 
this is not at all clear. One would have rather expected 
that when there was an abundant supply of food on 
the island the flies would have been less hungry, so that 
fewer would have been attracted by men, and the catch 
would have been less instead of greater the more crocodiles 
there were within reach. On the other hand, had this 
relation been noticed at one spot on a continuous length 
of mainland shore it could quite well be explained by 
the wanderings of flies in search of food which, finding 
abundance at one spot, remained there. 

But, as has been pointed out, there is no ground for 
believing that flies cross to Tavu over the open water 
separating it from the larger Kome and Bulago. 




AN AM HATCH TREK. 





^'^ 



FLY BEACH ON KIMMI. 
Behind a row of Ambatch trees on the right. 






To face p. 48. 



ITS ENEMIES 49 

It is noteworthy also that this explanation, were it 
possible, would, be opposed by the fact that the 
number of females caught on Tavu varied very little, 
unlike the male figure, whereas if the flies had been more 
attracted to Tavu on days when the crocodiles were 
numerous, there should have been greater variations in 
the female catch ; perhaps an inverse relation to the 
number of crocodiles. 

The explanation, however, may be connected with 
the pairing of the flies, Male flies flock to the coast from 
out of the forests when crocodiles are there in numbers 
in order to meet the females, which go to feed on the 
crocodiles. When crocodiles are fewer on the coastline 
the male flies may confine themselves more to the forested 
centre of the island : the boys caught always on the 
east and west shore and not in the central forest. It 
will be remembered that on Bulago and Kimmi the flies 
seemed to frequent different parts at different times. 

Having considered two influences that affect the num- 
bers of the fly, viz. food and climate, it will be interesting 
now to deal with the natural enemies of Glossina 
palpalis in all its stages. 

Considerable attention was paid to this question, and 
I have spent very many hours observing, in the haunts 
of the fly, birds and insects that might be expected to 
destroy the fly. 

Very many insects suffer great mortality in their im- 
mature stages of egg, larva and pupa, but it will be 
obvious from what has been said about the reproduction 
of Glossina that it is hardly likely that any great destruc- 
tion can be wrought upon egg or larva while within the 
body of the adult fly. It seemed possible, however, that 
the fat grub in the fly might be " stung " by some 
parasite such as the Hymenopterous " Ichneumon flies," 
and that after it had been extruded the adult parasites 
might emerge from the pupa. 

5 



50 NATURAL HISTORY OF GLOSSINA PALPALIS 

Accordingly I made some efforts to obtain the larvae 
from pregnant flies captured when the larva was far 
advanced in growth and kept in a cage, fed at regular 
intervals, until the larva had been extruded. But 
premature expulsion of the larva, ending in its death, 
took place so often that the attempt was given up. 

The next opportunity afforded to enemies is the brief 
moment after the larva has been extruded and is scramb- 
ling over the surface of the sand in the endeavour to find 
a spot where it can penetrate and hide itself. I have 
watched this happen ; the birth of the larva in the eight 
cases witnessed took place between 10' 45 a.m. and 1 p.m. 
It is very active, but being white with black bosses 
at the posterior extremity, is quite conspicuous as it 
wriggles over the surface. On several occasions I have 
placed the larva in front of a species of ant, Paltoihyreus 
tarsatus, and seen the ant pick up the larva, give 
it several nips with its large mandibles, and carry it 
off. Once, on arrival at the breeding ground, among 
some bushes where I used to lie and watch for events, 
I saw one of these ants wandering about with a larva 
in its mandibles. 

This ant was very often seen on the beaches where the 
fly breeds, wandering about and evidently searching for 
food, and no doubt it does occasionally destroy a larva, 
as was once seen. But it cannot often enough happen 
to meet a larva before it disappears into the ground to 
be of value as a controller of the numbers of the fly. Birds 
also may occasionally pick up the larva while it is thus 
exposed, but it can only happen rarely. 

The greatest destruction of Glossina by enemies probably 
takes place during the several weeks that it lies just below 
the surface of the soil as an inert pupa, but I have obtained 
no evidence of any vertebrate enemy. No traces have 
ever been seen on a breeding ground such as would be 
left by a bird scratching the surface as do game birds. 



ENEMIES OF THE PUPA 51 

It will be said that there were no guinea fowl or 
francolins (save a single forest francolin) on the islands. 
Nor have any evidences of the activities of such an 
animal as a shrew been found on the breeding 
grounds. The most important enemies, therefore, will 
be insects, and accordingly efforts were made to breed 
out from the pupae such enemies as the Chalcididae, 
Hymenopterous parasites or " Ichneumon flies " of 
minute size which lay their eggs in the immature stages 
of other insects, particularly the eggs and pupae, as butter- 
fly breeders know to their cost ! 

On Damba Island five thousand eix hundred pupae 
were kept in boxes with closely fitting glass lids, but 
not a single one yielded any Chalcids, although from the 
pupa of another species of fly obtained with Tse-tse 
pupae a species of Chalcid did emerge. 

However, I felt certain that Glossina pupae were attacked, 
for occasionally an empty pupa case was found with the 
minute circular hole in the shell through which the Chalcids 
had emerged. At last, on Wema Isle in 1914, when Fiske 
and I were opening numbers of pupae to observe the stage 
of development, he found one filled with rows of little 
white Chalcid pupae, looking like mummies with black 
eyes. I obtained more pupae from that locality and 
succeeded in rearing some of the Chalcids, which proved 
to be a new species that has been named Syntomosphyrum 
glossinae. 

It has been mentioned that some Glossina pupae were 
found with the minute round hole made by the Chalcid, 
but others are quite commonly found with holes of much 
larger size and of jagged outline. I have never been 
able to ascertain what is the insect responsible for this, 
but in the case of the allied species Glossina morsifans, 
a species of Mutilla (ant-like, wingless, fossorial Hymenop- 
tera) has been found to be responsible. The female 
Mutilla deposits her egg in the Glossina pupa, and its 



52 NATURAL HISTORY OF GLOSSINA PALPALIS 

larva destroys the Glossina. It has since been found out 
that the Chalcid Syntomosphyrum destroys not the 
Glossina but the Mutilla, which has itself destroyed the 
Glossina, so that this Chalcid works on the side of and 
not against Glossina. 

When the adult fly has broken through the end of the 
pupa case and pushed its way up through the loose soil 
covering it, it seeks for a stem up which to crawl so that 
it may rest with the wings hanging vertically downwards 
while they stretch and dry. At this time the fly is a 
soft white juicy morsel, and any ant that happened upon 
it would find a pleasant meal. But the fly seems to 
realize its danger, and is very much on the alert. More- 
over, its legs are surprisingly firm, although it appears 
so weak : I have several times watched newly hatched 
specimens resting on a pebble until the wings had har- 
dened, and if an ant came near enough to be dangerous 
they would quickly sidle away. 

An interesting insect, the " ant lion," makes its conical 
pits in the dry loose sand used as breeding grounds by 
Glossina, and lies in wait at the bottom ready to seize 
such insects as fall into the pit. Since these pits are often 
very numerous in the soil over which the freshly emerged 
fly has to scramble, the helpless insect must sometimes 
fall into one of these pits and be devoured before the 
wings have expanded, and I have actually seen one as 
it scrambled along fall down a pit. But the " ant lion " 
had either pupated or was not hungry, for it paid no 
attention and the fly scrambled out again. 

These pits are often so abundant in the very spots 
selected by the fly for its larvae to burrow in that I think 
it cannot be uncommon for the freshly hatched flies to 
fall in and be devoured. 

Much time has been spent in observational work on 
possible enemies of the adult fly. On Damba Island 
forty-four insectivorous birds feeding in the fly belt were 



ENEMIES OF THE FLY 53 

examined, and the stomachs searched for the wings of 
Glossina, easily recognizable by their peculiar venation, 
but none were ever found to have swallowed Olossina. 
Twenty more birds were shot on Bugalla with similar 
results. 

A common green tree frog was examined, and in fifty- 
three cases no Glossinae were found in the stomachs. This 
species spends the day among the vegetation on the 
shore, but I think only feeds at night, so that it is not 
likely to meet with Glossina. 

A large Agamid lizard haunts trees, around which there 
is a certain space of open ground, and I shot five of them, 
but their stomachs were found to contain only ants. 

It does not seem probable, in view of the above evidence, 
that vertebrates play a great part in keeping down the 
numbers of the adult fly. 

Of invertebrate enemies of the fly there is no doubt 
that species of Bembex, sand-wasps or Fossors, are of 
some value, but their distribution is very local. 

A full account of these most fascinating insects will 
be found in the chapter on Hymenoptera : it suffices to 
say here that two species ^ have been seen to store up 
Glossina in their underground burrows, and that they seem 
to know that fat full-fed flies, which they prefer for the 
food of their larvae, are to be obtained from man and 
other animals. I have seen the same in the case of a 
species (unidentified) which preys upon Glossina morsitans : 
as one walked along, pursued and harassed by the Tse- 
tse, the Bembex would accompany one, flying round and 
round searching for a fat fly. 

A species of Dragon fly (Cacergates leucosticta) which 
is very common on the lake shore has discovered the 
same thing, and individuals have several times been seen 
to chase Glossina, and once or twice I have actually seen 
them catch and devour the fly. On one occasion I was 

* B. forcipala, B. capensis. 



54 NATURAL HISTORY OF GLOSSINA PALPALIS 

able with glasses to see Cacergates in attendance on a 
hippo that was grazing on Bugalla fly ground, evidently 
on the look out for flies full of hippo blood ! 

Predaceous two-winged flies of the family Asilidae 
have once or twice been seen to be devouring Olossinae, 
but I do not think that the Asilid is of any importance 
as a regular enemy. 

On the whole, it seems that the chief enemies of Olossina 
are among the Hymenoptera, but I am inclined to think 
that great loss of life does not result. Olossina has 
such an extraordinarily slow rate of reproduction that 
it can have few enemies : the greater the number of 
offspring the more must be destroyed by enemies if the 
species is to be kept within bounds, and vice versa. Clim- 
atic conditions, in my opinion, together with facilities 
for breeding, are the most important influences affecting 
the numbers of the fly. 

We now come to the question of the " breeding grounds " 
of palpalis, on which a great deal of work has been done. 

The very peculiar method of reproduction of the genus 
Olossina was reported by Bruce in his papers on Nagana ; 
hitherto Olossina morsitayis had been supposed to deposit 
its eggs in buffalo droppings, and this was held to account 
for the supposed fact that this Tse-tse could not live 
apart from the buffalo. 

When palpalis was proved to be the carrier of Sleeping 
Sickness efforts were made to discover its pupae, with a 
view to the possibility of destroying it in large numbers 
when it could be easily reached. 

Dr. A. G. Bagshawe ^ in Uganda was the first to find 
the pupae of palpalis : they were deposited around the 
bases of stems of banana plants. Later he found them 
sparsely under sundry bushes and masses of creepers, 
but never in such great numbers as can now be found. 

Dr. C. Marshall and Lieutenant A. D. Eraser, R.A.M.C, 

1 Reports of the Sleeping Sickness Commission, 1908, IX, p. 48. 



tHM-%-^- 






GLOSS/.\U PALPALIS AND PUPAE. 

Slightly less than natural size. 

Photograph by A. Robinson.- 




UPROOTED TREE ON KIMMI l^I.K 

FORMING IDEAL SHELTER FOR 

PUPAE. 




H»W 



t 



SEARCHING luK I'LIAL AMONG 

GRASS TUSSOCKS ON SOUTH 

POINT, BULAGO ISLE. 



To lace p. 54. 



BREEDING PLACES 55 

were the first to find large numbers of pupae,^ and reported 
as follows : " They were most readily found on the 
shore within a yard or two of the edge of the forest. It 
has since been found that the nearer the forest the more 
plentiful they are . . . and that the most favourable 
place is close to the undergrowth that edges the forests 
— in the loose dry sand near the roots of ferns, etc., and 
shaded to some extent by the tall forest trees." This 
excellent account may now be enlarged upon as a result 
of many months' work and thought devoted to the breed- 
ing places of palpalis. 

It may be pointed out firstly that there are two broad 
distinctions possible — between large areas of shore suit- 
able, for reasons to be indicated later, along much of its 
length for the pupae, and isolated spots at the bases 
of trees, individual rocks, etc., such as the spots first 
described by Dr. Bagshawe. 

The former large areas may be termed " breeding 
grounds," the latter I have termed " loci," and they will 
be considered in detail. 

The requirements of the pupae of Glossina palpalis 
may be summarized as follows : " Loose dry soil, well 
shaded, but with the surface thoroughly ventilated ; 
within a few yards from the water but beyond its reach." ^ 
It is obvious that the soil must be loose, else the larva 
would be unable to burrow down. Hence, however 
suitable a spot may be in many other ways, if it is hard 
and bound down by rootlets of grass it will not be a 
good place for larvae to burrow into the soil. 

The character of the soil is important ; that it must 
be dry and well ventilated has been proved over and over 
again. A very interesting observation on Tavu Island 
in 1914 showed this very well. Close to a very favourite 

^ Progress Report on the Uganda Sleeping Sickness Camps, by Dr. 
A. D. P. Hodges, 1909, Appendix C, "The breeding grounds of Qlossina 
palpalis.''' The Sleeping Sickness Bureau, 1909. 

2 See my Fifth Report, p. 91. 



56 NATURAL HISTORY OF GLOSSINA PALPALIS 

breeding ground on a ridge was an area of low-lying sand 
covered by dense vegetation, the leaves of which lying 
on the sand were mouldy and kept it damp. My fly 
boys searched for pupae there unsuccessfully, and in so 
doing of course cleared away the dead leaves and opened 
up the vegetation, so that a small area of sand about 
two feet in diameter was much more freely ventilated, 
though still shaded. 

On a subsequent visit a week later I found, in that very 
spot, about two dozen fresh pupae which had been deposited 
there since my former visit. Incidentally this observa- 
tion shows a very important point which will be alluded 
to later, that the female fly searches carefully for the 
most suitable spot for the pupae. 

The soil itself may be of very diverse kinds : fine 
pebbles, pebbles mixed with coarse sand, coarse brown 
sand, coarse white sand, fine white sand, light friable 
earth, vegetable humus and debris, and the very fine dry 
dust found in caves and probably mostly derived from 
disintegrated droppings of bats. Coarse sand with or 
without pebbles has been found to yield the greatest 
number of j^upae : the very fine white sand such as com- 
poses the southern beach of Nsadzi (see Fig.) is not so 
suitable, because I think it holds moisture too much. 
The very fine dry dust of caves does not seem very attrac- 
tive to the flies ; possibly it is in its turn too dry. 

Vegetable humus and debris are most important, for on 
long stretches of shore they often form the only material 
suitable for pupae, elsewhere there being only bare rocks. 
Little pockets of humus and dried-up debris under angles 
of rocks or at the bases of trees in such areas form the 
only spots in which the fly can deposit its larvae, and 
these are what I have termed " loci." Other " loci " 
are sometimes formed in a'forest by loose sand up against 
the base of a tree trunk not far from the water, often 
indicated as suitable for palpalis pupae by the presence 




TREE TRUNK ON BUGALI.A ISLE UNDER WHICH MANY GLOSSIXA PUPAE 

COULD ALWAYS BE FOUND. 

By permission of the Royal Society and the Controller, H.M. Stationery Office. 




BREEDING PLACE OF GLOSSIXA AT HOLLOWED BASE OF TREE ON BUGALLA. 
By permission of the Royal Society and the Controller, H.M. Stationery Office. 

To face p. 56, 



BREEDING PLACES 57 

of the pits of " ant lions," which have much the same 
requirements. 

On the little Isle of Lula, where fly was found in 1918-19 
to be so numerous that the catch was at the rate of 56*5 
males per boy-hour, there is nowhere for the fly to deposit 
larv£e except in *' loci " — there is no sand or gravel beach 
anywhere on this rocky little island. 

This figure however is exceptional, but I have no doubt 
in my own mind that palpalis can exist in considerable 
number on a coast line where there are only scattered 
" loci " in which to place its larvae. 

The next point to be considered is shade, which is of 
great importance. The pupa is dependent upon protec- 
tion from the sun, although, as I have shown above, it 
can survive a certain amount of exposure. 

Shade for pupae may be either permanent or variable. 
Permanent shade is afforded by (1) caves or large rocks 
undercut at the base ; (2) prostrate tree trunks arching 
over the ground ; (3) hollows at the base of or among 
roots of living trees ; (4) the pent-house roof formed by the 
disc of earth torn up by the roots of an overturned tree ; 
(5) thick bushes. 

I have not found caves to be nearly as productive as 
I had expected ; on Kimmi Isle, where flies were caught 
at the rate of 33 males per boy-hour, pupae could only be 
found at the rate of 6-7 per boy-hour. On the other 
hand, at a locality on Wema where the fly rate was 59-5 
per boy -hour, jnipae were found at the base of an under- 
cut rock at the rate of 72-4 per boy-hour. I think the 
soil in caves is almost too dry. 

Prostrate tree trunks arching low over the ground 
form ideal sites for pupae, and the one illustrated was a 
favourite collecting ground on Bugalla, On the same 
beach on Bugalla and close to it was a tree much hollowed 
at its base, which is figured ; it proved to be a very good 
collecting ground for pupae. 



58 NATURAL HISTORY OF GLOSSINA PALPALIS 

When a tree is torn up by the wind and, unable to 
fall, is held up by its neighbours, the roots and earth 
embraced by them form an ideal shelter for pupae if the 
tree is near enough to water. One such was found on 
Kimmi in 1918-19 and is here illustrated. In the loose 
dry earth forming an area of a few feet square under the 
roots, four boys in half an hour secured 309 pupae, giving 
a rate of 154-5 per boy-hour, which is extremely high. 
Search was made for pupae in other localities near this 
tree, but the result was only 28 per boy-hour ! 

Lastly, thick bushes, especially the " Oluzibaziba " 
(Alchornea), provide shade all the year round, and if the 
soil and other conditions are suitable, pupae may always 
be looked for there with success. 

The illustration shows a very favourite collecting ground 
on the fly beach of Damba Island : under the bushes 
close by but out of reach of the water. 

Variable shade is formed by low undergrowth or creepers 
or dense young growth of bushes near the ground. I 
have been much struck with repeated evidence of the fly's 
care in selecting spots where new young growth is rapidly 
forming dense shade, and the quickness with which such 
shelter is seized upon by the mother as suitable. 

It was a common occurrence to find a cluster of some 
creeper forming a dense tangle of fresh green that provided 
admirable shade for the pupae, and investigation of the 
pupae found there showed that they were in a very early 
stage of development ; that is to say, had been recently 
placed there. On Wema a very thick tangle of young 
sprouts of a species of Polygonaceae was found on a ridge 
of sand, projecting so as to arch over the surface below : 
one boy found here eighty-eight pupae, of which 91 per 
cent, had only recently been deposited, for they were 
in a very early stage of development. 

Moreover, only six empty cases were found from which 
the adult fly had emerged. These facts show that the 








' •" '' 'I 



ENZIBAZIBA" BUSHP:S OX DAMBA ISLE FORMING BREEDING GROUND. 
By permission of tlie Royal Society and the Controller, H.M. Stationery Office. 




SHINGLE AND SAND UNDER SHELTERING ENZIBAZIBA BUSHES WHERE FLIES 
HAVK BEEN SEEN TO DEPOSIT LARVAE. 

Foot-rule set upright shows scale. 

To f.ice p. 58- 



BREEDING PLACES 59 

green growth had only just reached the condition deemed 
suitable by the fly as cover for the pupae. An opposite 
condition was found on Bulago. A tree had large horizon- 
tal branches near the surface of the sand arching over 
which was a canopy of half dead creeper, throwing very 
poor shade, but with some fresh green shoots springing 
out so that in a very little while it would form a good 
shelter. Forty-five pupae were found here, of which 
twenty-seven were dead ; in three the adult fly was almost 
ready to hatch, and the other fifteen were in the earliest 
stage of development. 

These facts show that the herbage had been at one 
time dense enough to throw good shade, but having died, 
many pupae beneath it had been killed by exposure to 
the sun's heat. Now that fresh green shoots were growing 
again, the fly considered the shelter good enough, and had 
begun to use the spot again as a nursery. 

At another time a boy searched for pupae at the base 
of a papilionaceous tree, which having thin foliage throws 
poor shade, and in this case had recently died. Here 
were found 130 shells from which the adult fly had emerged, 
and five pupae, all dead. Owing to the death of the tree, 
and the poor condition of rambling plants around its 
base which had at one time thrown good shade, the fly 
no longer considered the spot a suitable one, and all the 
pupae that had been deposited there when the shade was 
good had either hatched out or died. 

Lastly, among the requirements of the pupae is proximity 
to water. The pupa seems to require this, although its 
actual surroundings must be dry. Now, inasmuch as 
the optimum conditions of boil and shade are provided 
by the raised beaches of sand or gravel that have been 
left by the subsidence of the lake from a former higher 
level, these raised beaches being naturally near the water 
it might be argued that the pupae were found here not 
because the beaches were near the water, but because on 



60 NATURAL HISTORY OF GLOSSINA PALPALIS 

the beaches were found the optimum conditions. But a 
recent observation, I think, disposes of that argument. 
On Kimmi Isle in 1914 was a broad flat strip of low lying 
marshy land, soft and waterlogged, that obviously owed 
its origin to the level of the lake having fallen and the 
water having receded from the real shore marked at 
the edge of the forest by the usual raised beach, which 
was thus separated from the water by a hundred yards 
of marshy grass land. 

This raised beach satisfied aU the requirements of pupae 
except proximity to the open water, but no pupae were 
found in 1914. In December 1918, however, there having 
been an exceptionally wet season in 1916, the water 
had returned to a former height and had covered the 
former marsh land, so that it came right up to the old 
beach, which thus formed a typical " fly beach." It 
was now used by the fly as a breeding ground, and pupae 
were found there. 

It may be said, then, that the ideal requirements of 
the fly for its pupae are found on the beaches near the 
water, well shaded, and composed of dry sand or gravel, 
and that where these occur palpalis is found in maximum 
numbers. But in their absence the fly makes use of such 
scattered nooks as can be found, so that it can exist 
in some number in the absence of " breeding grounds " 
on rocky coasts. I consider this to be very important, 
for it has been thought that it would be possible to 
destroy the fly by merely cutting down and clearing the 
low shade producing vegetation on the beaches so as to 
spoil the breeding grounds. This would doubtless lessen 
the numbers of the fly, perhaps by half, but would not 
exterminate it. 

In order to exterminate Sleeping Sickness two animals 
must be kept from each other — the Situtunga antelope 
from which the fly obtains the Trypanosome, and the 
fly, which inoculates the Situtunga with the Trypanosome. 



GLOSSINA OR SITUTUNGA ? 61 

Each without the other is harmless, for the Trypanosome 
cannot multiply indefinitely in the fly, and requires to 
live for a cycle in mammalian blood. 

Can the Situtunga be exterminated ? This would 
be an extraordinarily difficult matter. It might be de- 
stroyed, temporarily, on the islands, for there are very 
iew localities where it would be out of reach. But on 
the mainland there are vast areas of papyrus swamps 
in which it finds sure refuge and where it would be quite 
beyond reach. Now it is well known that the antelope 
swims readily, and I have given an example of its wander- 
ings on to islands where in the old days it was kept down 
by natives. Hence it would easily swim out again to 
the islands from the mainland papyrus swamps, and from 
one part of the mainland to the other. If, however, a 
price were put upon its head and natives were allowed 
to destroy it, it might conceivably be kept to the papyrus 
swamps, where, beyond the reach of Glossina, which is 
never found in such localities, it would be harmless. 

As to the other side of the question, whether Glossina 
can be destroyed, or at least so diminished in numbers 
as to be harmless, there is a good deal to be said. It must 
be remembered that when the fly is only present in small 
numbers the chances of any one being infective are minute. 
For every fly does not feed from a buck, and every buck 
that is fed upon does not contain Trypanosomes. More- 
over, as Miss Robertson has shown, if the buck does 
contain Trypanosomes they are not always in a condition 
ready to multiply in the fly when it bites, and lastly, 
every fly that takes in Trypanosomes is apparently not a 
suitable medium for their further development. 

When an undesirable insect is to be destroyed, it is 
often found that the larval stage is easy to deal with, or 
the next stage, when the insect is a quiet pupa or 
chrysalis. 

But since there is no free larval stage in Glossina, 



62 NATURAL HISTORY OF GLOSSINA PALPALIS 

the pupa is all that remains to us. Can we then 
destroy it ? 

This is theoretically easy since shade is a requisite. If 
all the low bushes and creeper growing on dry sand near 
the water were cut down, the " breeding grounds " would 
be destroyed and the numbers of the fly might be reduced 
by half. 

This would leave, however, all the " loci " that have 
been discussed, and I see nothing for it but to clear all 
the shore of low bush for at least fifty yards back from 
the water, and probably a great deal further. This would 
be a colossal task with a lake of such a size. But a better 
way occurred to me in 1914, and an observation in 1918 
on Kimmi that has been already quoted made it seem 
very likely to succeed. 

The method is to provide for the fly all the conditions 
that it requires in a concentrated form, in such a way 
that it will deposit its pupae in the place chosen for it rather 
than elsewhere. The pupae can then be easily collected 
and destroyed. The conditions required by the fly 
have been dealt with above, and they are provided by 
building a low roof of thatch covered with green creeper 
on a bank of sand or gravel near the water. In 1914, 
I had commenced experimental work on these lines on 
Tavu and Ngamba, which was cut short by the call of 
active service, but I had satisfied myself that these 
shelters were attractive to the fly. I also found that 
although, as has been said before, a thick layer of dead 
leaves on the surface is inimical to the pupae, yet the fly 
prefers the surface to be lightly strewn with flakes of bark, 
sticks or dead leaves. In the preliminary tests one half 
of the sheltered area was strewn with bark or leaves and 
the other half left bare, but there were always more 
pupae found in the former half. 

The accompanying figures show the nature of the 
" artificial breeding ground " thus provided in the test 




THE RAISED BEACH OF NGAMI5A CLEARED OF VEGETATION UP TO THE 

EDGE OF THE FOREST BEHIND. 

Two boys are senrching for pupae under the shelter. 

Rv t'cniiissioti of the Royal Society and lite Controller, H.M. Stationery Office. 




?^''IZj 







THE SHELTER ON THE RAISED BEACH OF TAVU, AFTER CLEARING. 

The water lies beyond the reeds on the right hand. 

By permission of the Royal Society and the Controller, H.M. Stationery Office. 

To face p. 62. 



PROPOSED NEW METHOD OF DESTRUCTION 63 

experiments on Tavu and Ngamba in 1914. When I 
returned to the islands after the war this question was 
much in my mind. It had seemed probable that in 
order to prevent the fly making use of natural breeding 
grounds and loci it would be necessary to clear them, 
but a most enlightening observation on Kimmi in 
December 1918 made it seem probable that clearing 
would be unnecessary. On a sand bank or raised beach 
the boys were set to find pupae, but found only a few 
except at one spot. This was under a little pent-house 
roof formed by roots of a tree that had been torn up by 
the wind but had been prevented from falling by its 
neighbours. The earth embraced by the roots formed a 
roof at an angle of forty-five degrees protecting from the 
sun and rain loose dry soil, and in an area a few feet square 
one boy found pupae at the rate of 104-5 per boy-hour. 
This proves that although there may be a large area of 
well sheltered sand apparently suitable for pupae, the 
fly will carefully search for the best spot and deposit 
pupae there in numbers rather than scatter them along 
the larger area. 

I also found numerous other examples of the same thing : 
moreover, an experiment has been cited earlier which 
shows that the female fly does circulate round an island, 
partly no doubt in search of food but also no doubt to 
look for the best place for her young. Indeed, I feel sure 
that the mother fly searches as carefully as does a parent 
butterfly for the right plant on which to lay her eggs. 
That being so, there is no need to cut down the bush, 
if the artificial breeding place is made tempting enough. 
The construction is very simple. All roots are pulled 
up out of the loose dry soil. The roof covers an area 
some twelve by four feet ; at its back it is just high enough 
to allow a boy to creep under in search of pupae, in front 
it just clears the ground. There are no walls, to allow 
the free ventilation required. Creepers such as the 



64 NATURAL HISTORY OF GLOSSINA PALPALIS 

Ipomaea and others which grow abundantly in these 
localities are trained so as to make a thick mass of young 
greenery on the roof, and the soil is lightly strewn with 
bark, dead sticks or leaves. At regular intervals of a 
week or ten days these shelters can be visited and all 
pupae easily collected by boys searching in the sand. 

Should the method prove feasible as a means of destruc- 
tion on a large scale, it might be possible to put sieves 
or f)erforated trays in the sand under the shelter of a 
kind that would allow the pupae to be quickly sifted 
out. Or another method might be tried of destroying 
the pupae by the sun's heat. The roof could be made in 
two halves, and at regular periods one half could be lifted 
off so that the pupae beneath would be killed by prolonged 
exposure to the sun's heat, while next time that half 
would remain covered and the other half be taken off. 
The rainy season, however, would introduce complica- 
tions into this method, for often there are days with very 
little sun, and if the sand was allowed to get wet, the 
flies would no longer deposit pupae therein. The method 
is a simple and inexpensive one, and should at least 
greatly reduce the numbers of the fly. There is no doubt 
whatever that these shelters are very attractive, and 
approved of by the fly as suitable for their young. Be- 
fore I came away from the islands in 1919 for leave, a 
number of artificial breeding grounds were prepared 
on Bulago and Kimmi and are now being tested. The 
pupae are collected weekly from each, and also from an 
ideal natural breeding ground on each island for com- 
parison, that on Kimmi being the upturned tree roots as 
described. From figures that have reached me so ' far, 
it is clear that my artificial shelters are just as attractive 
as, or sometimes more than, the natural shelters, for on 
some occasions not so many pupae are found under the 
tree as under one of the shelters close by. During July 
over two thousand pupae were destroyed on Kimmi by 
this method, Kimmi being barely a mile in diameter. 



PROPOSED NEW METHOD OF DESTRUCTION 65 

Seeing that the fly is such an abnormally slow breeder, 
and that this method destroys generations yet to come, 
it does seem possible that it will result in very substantial 
reduction in the number of flies. Of course a few pupae 
will continue to be placed in other spots, scattered " loci," 
but with the reduction in number of flies the number 
of these would be reduced in far greater proportion, 
until when there are only very few flies about it seems 
reasonable to suppose that the number of pupae not 
deposited in the shelters would be so small that the fly 
would be exterminated altogether. This would probably 
take some years, but the decline would be a steady 
one. 

The method could be made applicable to Glossina 
morsitans also, only in this case the shelters would need 
to be placed not near the water, but near some well 
marked game track ; for morsitans seems to place its 
pupae naturally near game tracks. 

This chapter on the Tse-tse fly may fittingly be con- 
cluded with the following verses : 

TO GLOSSINA : A CURSE ! 

Thou dipterovis hexapod (by which I mean 

Thou six-legged creature borne on pinions twain), 

Thou tracheate arthropod, — in short, thou FLY, 

With buzz importunate arousing my 

Just wrath ; may fiends innumerable rend 

Thy quivering form in twain, and, ruthless, send 

Its disunited fragments to the place 

Whex'e bad flies go, whate'er their name or race ! 

May my sanguineous fluid, y'clept blood, . 

Which thou desirest to extract for food. 

Plunging thy sharp proboscis through my skin 

To reach capillaries enshrined within, 

Flow freely till thou burstest ! 

Or, again. 
Lest this should cause thee insufficient pain, 
May justice serve to thee another fate 
That red corpuscles ne'er cqrpusculate 
In thj- capacious proventriculus, 
So that, attenuate, ridicvilous, 
6 



CG NATURAL HISTORY OF GLOSSINA PALPALIS 

Thou'i't gnawed to death by cruel starvation's fangs ! 

Yet do I wish for thee severer pangs 

Since none of the above are adequate 

Or quite sufficient to express my hate ! 

May Bembex wasps (those skilful hunters) thrust 

Into thy side the lancets which, I trust. 

Will fail to paralyse thy sense of pain 

While rendering thee inert, that sod, in vain 

Thou strivest to escape from htmgry jaws 

Of Bembex' child, devouring without pause 

Thy non-essential tissues ; till, at length 

When it shall have attained its perfect strength. 

Thy shrinking vitals are devoured by it. 

And there is left of thee no little bit 

AVhereof a man might say, '' This was a FLY, 

A noble creature that knew how to die " ! 

So that there shall not e'en be left of thee , 

So vain a thing as a fond memory ! 

Thus would I wreak my vengeance on thee, pest. 
That oft hath bitten me with fiendish zest ! 



Addendum. 

The first observations on the use of artificial breeding 
places were made in 1914, but were interrupted by the 
war. 

During the war my friend, Dr. W. A. Lamborn, in 
Nyasaland, unknown to me, was experimenting on his 
own lines by cutting down trees to make artificial breeding 
I)laces for G. morsitans. (See Bulletin of Entomological 
Research, May, 1916, VII, p. 38.) This method had been 
developed by him independently, for my re]3ort, delayed 
in publication by the war, was not pubhshed until 1919. 
(See Reports of the Sleeping Sickness Commission of the 
Royal Society, 1919, No. XVII, pp. 67-71.) I did not 
hear of Dr. Lamborn' s work until after I had been 
able to develop and make first use of my scheme early 
in 1919. 



CHAPTER IV 

THE LAKE 

Some facts as to the great Lake Victoria will probably 
be found of interest before reading a general account of 
the scenery and life thereon. 

The following data are taken from the eleventh edition 
of the Encyclopcedia Britannica : 

Lake was discovered by J. H. Speke on August 3, 1858 ; the Ripen falls, 
the only outlet, discovered by him on July 28, 1862. 

Area over 26,000 square miles, only exceeded by Lake Superior. 

Greatest length from north to south, 250 miles. 

Greatest breadth, 200 miles. 

Coast line of over 2,000 miles. 

Height above sea level, about 3,720 feet. 

Greatest known depth, 270 feet. 

Largest islands — 

Ukerewe, near Muanza on south coast, whose greatest diameters 

are 25 X 12 miles. 
Buvuma, in the Napoleon Gulf on north coast, which has an area 
of 160 sqviare miles. (The Isle of Wight has 147 square miles.) 

The Sesse Archipelago contains 62 islands, of which 42 were inhabited. 

Area drained by the lake, including lake itself, 92,210 square miles. 

Rainfall over whole area averages 50 inches yearly. 

Annual rise and fall from 1-3 feet : maximunri height in July. 

By far the greater part of the water that enters is lost by evaporation. 

The largest affluent is the River Kagera, which enters 
on the west coast, and was crossed by Speke on January 
16, 1862, on his way to the discovery of the Ripon falls. 

He says of it : " Once over I looked down on the noble 
stream with considerable pride. About eighty yards 
broad, it was sunk down a considerable depth below the 
surface of the land, like a huge canal, and is so deep, it 
could not be poled by the canoe-men ; while it runs at a 
velocity of from three to four knots an hour." 

This fine river, reckoned as 430 miles long, derives its 
waters ultimately from the south-eastern slopes of the 

67 



68 THE LAKE 

Mfumbiro range north of Lake Kivu, and from the country 
between Lake Kivu and the north end of Lake Tanganyika, 

It is formed by the union of several other rivers, and 
at first flows northwards and slightly westwards and then 
turns abruptly eastwards, to flow eventually into the 
lake at about the middle of the western shore, a little 
north of Bukoba. It is of considerable geographical 
interest that whereas the main affluent of the Victoria 
Nyanja, and thus the chief ultimate source of the Nile, 
arises from the south-eastern slopes of the IVIfumbiro 
Mountains, the other side of the same mountains gives 
origin to streams of which the most important is the 
Rutchuru, flowing into Lake Albert Edward. 

From this lake the Semliki river flows into Lake Albert, 
adding its waters to those brought from Lake Victoria 
by the first part of the Nile, via Lake Kioga. 

So a very large part of the waters of the Nile above 
Khartum have passed through Lake Albert. 

The numerous islands among which I worked vary 
much in size, from Bugalla and Kome down to mere rocks 
or shoals of sand. The commonest type is composed 
of central grassy uplands rising a few hundred feet, with 
a belt of forest along the water of breadth varying accord- 
ing to the lie of the land. But some islands have practi- 
cally no forest growth ; thus, Kiuwa is conspicuous as 
being merely a conical, grass clad hill, with a thin fringe 
of bushes near the water. On the other hand, Damba 
is quite flat and almost entirely covered with dense 
forest. Wema has one peculiarity ; one of its four 
hills is crowned with forest, the base and the surrounding 
terrain being grass clad. On the largest isles there is 
much park-like country ; that is to say, the grass land is 
dotted with fine trees, or clumps of small trees and bush 
forming copses, and the grass being thin and only knee 
high, this is delightful country for walking. The shores 
of the islands vary much in appearance, but are rarely 




THE KAGERA RIVER AT KIFU.MBIKO (KYAKA KORT), ABOUT 
FORTY MILES FROM THE LAKE. 




THE HEAD OF NAPOLEOV GULF WHERE THE NILE ARISES FROM THE LAKE. 
To the left of the tree a faint haze indicates the site of the Ripon falls. 

To face p. 68 (tirst pag 




THE EASTERN CATARACT OF THE RIPON FALLS IN I9IO. 




THE BIRTH OF THE NILE. 

Ripon Falls from below. 



To face p. 68 (second page)- 



SCENERY 69 

anything but beautiful. The most picturesque scenery- 
is the narrow channel between two islands where the 
blue water is bounded on each side by dense vegetation ; 
for example, the lovely passage between Damba and Kome, 
only a few hundred yards wide. 

Forest lies on either side, and in front a narrow belt 
of bright green papyrus, growing at the water's edge. 
A belt of reeds springs from the slightly deeper water, 
and in front of this again the still blue surface is carpeted 
with leaves of water-lilies, whose blue or pink flowers 
stand up a little out of the water. 

An open shore, with beach of finest white sand or 
pebbles, is not uncommon, with a forest belt terminating 
abruptly som^e yards away from the water. Here there 
is always evidence of the subsidence of the lake level 
in the shape of raised beaches at the edge of the forest. 
Such a strip of shore is termed a " fly beach," since it 
provides ideal conditions of food and shelter for the 
Tse-tse. 

In some places the shore is formed of bare rock of a 
spongy texture and red brown in colour, shelving gently 
into the water, or sometimes forming small cliffs. Here 
and there a stream of lava makes a strip of lighter colour, 
embedded in which are fragments of quite different 
rock, like plums in a duff. 

A sm-all headland on which was pitched my camp on 
Damba ended in a face of grey rock perhaps 20 feet 
high, in which was a crevice filled with water- worn 
pebbles at least 12 feet above the present highest level 
of the lake, showing how the water had receded. 

On a flat rocky coastline the forest often comes quite 
to the water's edge, the trees actually overhanging the 
water, and there are usually abundant ferns. Long 
stretches of very low lying marshy shore are common, 
and are more or less under water during the high level 
of the lake in the heavy rains. Lush grass and reeds 



70 THE LAKE 

make these spots very attractive to hippos, and the 
soft soil is churned up along their regular tracks. A 
very curious plant flourishes here, for all the world like 
a small lettuce floating on top of the water. It propagates 
very rapidly, probably by budding, so that many square 
yards of water may be covered by it, and patches often 
are driven out to sea by a land breeze. The curious 
ambatch tree, with its short thick trunk of extraordinarily 
light, pithy wood, scanty leaves and j^ellow papilionace- 
ous flowers, flourishes on marshy shores, and the graceful, 
tall, smooth " Makindu " (wild date) palm is plentiful. 
Only one other species of palm is met with on the islands, 
a species called " Ekibo " by the natives, having a short 
stem and very large dark green leaves, whose mid-ribs 
are often used as rafters for houses, or, when young, 
furnish the fibre used in sewing the planks of the canoes. 
On low lying sandy or muddy shores a species of cane 
growing to a height of 10 feet sometimes forms thickets 
very unpleasant for one to penetrate owing to the sharp 
points of the narrow, hard leaves. Several bushes are 
very characteristic of the lake shore ; one ^ is known to 
the Baganda as " Oluzibaziba," and forms dense thickets ; 
it has leaves very much like those of a poplar in shape 
and setting, which are the favourite food of the Situtunga 
antelope. Another, called " Kinsambwe," has harsh, 
hairy leaves, with rather a rank odour ; and a third, ^ 
with leaves much like ambatch, was called by the natives 
" Omuvuvumye." Several flowering plants sometimes 
made patches of colour ; one like a small herbaceous 
sunflower grows in banks of bright yellow ; another 
(Ipomaea) rambles over bushes and spreads wide its purple 
convolvulus-like flowers, while a third, called " Anyam- 
berege " by the natives, sends up tall shoots on which grow 
flowers much reminding one of single hollyhocks ; bright 
yellow, with a velvety patch of purple brown at the 

1 Euphorbiacpae , Alchornea chordnta. ^ PapiUonaceae. 




YOUNG RAPHIA PALM (" KIBO ") ON THE RIDGE OF KIRUGU ISLE. 




WILD DATE PALM ON DAMBA ISLE. 



To face p. 70 (first page). 




A TAXGLEI.i MASS OF IPOMAEA IN FLOWER. 











x'^ 



."?«*^' 



■,^v'ilv(' 



0^ N. <. 






J 



A lJi:U UF BRACKEN" ON 1;Ul;ALLA in IKONI OF I HE FuREriT LEL I . 

To face p. 70 (second page). 



VEGETATION 71 

base of each petal. One other characteristic plant may 
here be noted, known to the natives as " E'tungulu " i 
It grows in dense patches, throwing up straight green 
stems as much as 8 feet high, furnished with alternating 
leaves of very thin texture, with a smooth shiny surface, 
bright green in colour, elongated, and with pointed tip^ 
The flowers are borne on short stalks coming up separately 
from the leaf stems ; they are in shape somewhat like 
that of a pentstemon, in colour whitish or dull pink 
according to the species. The fruits are pear shaped, 
attached by their broad bases in a cluster, and are of a 
very bright shiny red. If the tough skin is torn open 
the interior is found to consist of a large number of 
round black seeds embedded in a white pulp with delicious 
acid taste ; hence these fruits are much esteemed by 
the natives, and by monkeys. The fruit of the white 
flowered species is poor compared to that from the red 
flowers. 

To return to the forest belt. A characteristic feature 
of its landward side is the abrupt maigin ; one suddenly 
emerges from forest to open grass land as though the edge 
had been cut by a landscape gardener. 

It is. possible that this edge owes its origin to former 
systematic burning of the grass by natives, so that no 
outlying, straggling fringes survived. Now that the 
population is no longer there, however, the forest edge 
seems in places to be gradually advancing over the grass, 
the vanguard formed by rambling bushes of low growth. 
The significance of this had not occurred to me until 
Fiske pointed it out in 1914. 

On the smaller islets, if very rocky, the only trees are 
figs, which seem especially to thrive close to the water, 
and may sometimes be seen perched on a rock, which their 
descending roots embrace on all sides. These doubtless 
owe their origin to seeds dropped by some pigeon. 

^ Anonaceae. 



72 THE LAKE 

Owing to the moist climate the foliage is alv/ays green, 
and at no time are the trees as a whole bare of leaves : 
it is quite common to see one tree shedding all its leaves 
while another near by is in the full glory of new foliage. 

Flowers on the islands are disappointing ; they do not 
enter into the landscape, but there are many creepers 
which ramble over the tops of the forest trees and are 
covered with sweet scented white or yellow flowers : 
many trees and shrubs also have fragrant blossom.s, 
some of which are beautiful, often of waxy appearance. 

The colouration in the bright sunlight during one of 
the clear days characteristic of the heavy rains is really 
wonderful in its brilliancy. From high ground one 
looks over the top of vividly green forest towards distant 
purple islands set in a sparkling deep blue lake, which 
is stirred into white -capped waves by the prevailing 
south-east breeze. So clear is the atmosphere at this 
time, especially in the evenings, that from Bugalla Island 
some of the individual houses at Entebbe on the main- 
land, twenty-five miles away, could be distinguished with 
the naked eye, and the flagstaff at Government House 
could be seen with glasses, though I could never make 
out the flag itself. 

The climate of the islands is more equable than at 
Entebbe, the water exercising its usual influence. 
Consequently, although the average mean temperature 
is degrees higher than at Entebbe, the maximum is 
lower, and the nights warmer. The rainfall also is more 
equably distributed than on the mainland, although it 
is greater. There was no month without some rain during 
the twelve of which I kept meteorological records on 
Bugalla, but the greatest fall came at the same two 
periods as on the mainland. (See Chart I.) 

A striking feature is that, with extremely rare excep- 
tions, the rain falls between midnight and noon, often 
between midnight and daybreak, so that afternoon rain 




ABRUPT MARGIN OF FOREST BELT ON BUGALLA. 
A flowering bush of Haionga at the angle was much frequented by butterflies. 




v.: 'rSMblsidisai 



\\\) ON BUGALLA ISLE. 



To face p. 72. 



A THUNDERSTORM 73 

which occurs at Kampala on the mainland, a few miles 
from the lake shore, was unknown during my time on the 
islands. Another characteristic is that the rain is nearly 
always accompanied by thunder ; but though this is so 
frequent one never experiences the oppressive heaviness 
of atmosphere which precedes a thunderstorm in England. 
The following is a description of a typical, or as I used 
to call it a formal, thunderstorm, such as occurs with 
varying intensity every few days from mid-March to 
mid- June during the period of heaviest rains. The day 
has been brilliantly fine, with a hard blue horizon and 
vivid colouring, and an appearance of nearness of distant 
objects. There has been a steady breeze all day long, 
dying away towards sunset, which has perhaps shown 
for a brief spell a glory of flame-tinted cloudlets. After 
dark not a cloud is to be seen anywhere, and the stars 
shine brilliantly. Before turning in at about 8' 30 one 
takes a look round, but there is nothing to note except 
a distant flickering of lightning to the south-east, which 
is practically a nightly occurrence in the rainy season. 

Having seen that tent pegs and ropes are secure, and 
that the front of the tent can be quickly closed in an 
emergency, for these storms often give one little time, 
one turns in, to be not at all surprised at being awakened 
in the small hours, usually between two and three, 
by a rumbling of thunder. Stepping outside the tent 
one sees magnificent piled up masses of inky cumuli 
illum.inated by almost incessant flickerings of lightning. 
Sometimes a flash stretching in an arc right across the 
heavens makes one start with the wonder and, almost, 
fear of it. 

In the momentary intervals between the rumblings of 
thunder can be heard a faint musical sound, produced 
by the downpour of rain on the water, as yet far away. 
There is nothing to be done but to make sure that the 
tent is firmly secured, fasten up the door, enduring an 



74 THE LAKE 

" infinite torment " of mosquitoes which, aware of the 
coming storm, have thronged into the tent for shelter, 
and retire to bed again to await the onward march of the 
storm, for no more sleep is possible until it has passed. 
Overhead the stars are still shining brilliantly, and it is 
absolutely calm. Presently a faint murmuring of wavelets 
is heard ; heralds of the disturbance produced by the 
distant storm, by the time they reach the island reduced 
to mere ripples. Now a faint breath of wind can be felt, 
which dies away, followed by another puff, and the sound 
of the rain and thunder grows louder, while the light- 
ning increases in intensity until it almost hurts one's 
eyes, kept tightly shut. The ripples increase into waves, 
and the noise of surf on the beach is added to the distant 
sounds. A few fat drops of rain descend, and then with 
a rush and a roar the storm arrives. A hurricane of 
wind tears and shakes the tent until one expects every 
minute to be carried away with it ; the roar of the sheets 
of rain on the roof is almost loud enough to drown the 
deafening thunder produced by flashes of lightning that 
seem to split one's very head in twain. This pandemonium 
lasts for about a quarter of an hour, when the wind moder- 
ates a little, the rain increases in intensity, and the 
thunder gradually passes away as the centre of the storm 
moves off. After an hour or so the rain slackens, but 
continues very heavily until shortly before daybreak, 
though sometimes continuing steadily until the morning 
is well advanced ; the evening being again line and 
clear. In one such storm two and a half inches of 
rain fell between 6.30 and 9 a.m. Such is the formal 
storm of the wet season, but quite frequently there 
are dry thunderstorms, when the lightning apparently 
discharges from one cloud to another, and there is 
no rain. The thunder on these occasions has a hollow, 
light quality, probably due to the rarified air of the 
upper regions in which the storm occurs. The clouds 



CLOUDS 75 

are greatly disturbed, and one seems to be looking upwards 
into a vortex. There is usually a central area to which 
ragged pieces of cloud drift from all directions, only to 
be torn into shreds and vanish as if they had gone up a 
chimney. These overhead disturbances may be accom- 
panied by no disturbance whatever at earth level, where 
the sun shines and a fine weather breeze blows as usual. 
Sometimes the edges of the clouds at the centre of these 
storms may be wonderfully rainbow tinted, although no 
rain reaches earth. On Damba Island in June 1911 was 
seen one evening a wonderful cloudscape to the East. 
Low down, over the mainland, were the usual lumpy 
cumuli, and to the right these merged into nimbus. 
Converging to a point on the horizon between these were 
two broad filmy streaks, above and transverse to which 
were bars of cirro-stratus. This cloud complex was the 
forerunner of the highest wind I had experienced on the 
islands up to that time ; it began at midnight and re- 
peatedly awakened me : by mid-day the blue lake was 
whitened with curling wave crests, and drifting purple 
and green cloud shadows made lovely contrasts of colour. 
Since I was very dependent on the state of the weather 
for my work outdoors, I took some interest in the signs, 
and an account of what was learnt may be of interest. 

Firstly, the meteorological signs. 

There were the usual general signs, such as cirrus or 
cirro-stratus clouds and clearness of atmosphere, heralding 
storms ; heat haze in fine weather, etc. 

The approach of the rainy season is preceded by cloud 
funnels, which appear in all stages from a nipple shaped 
process at the lower edge of a ragged cloud, to a complete 
pillar connecting cloud and lake, called by the natives 
" Omusoke." From Entebbe, looking out over the 
lake, a great number of these are seen, and they are 
commonly called waterspouts, but I have never been 
near enough to make out whether they correspond to 
waterspouts at sea. 



76 THE LAKE 

There is a great deal to be learnt from the wind, its 
direction and force, and so on. The daily wind blows from 
the south-east, being strongest in early afternoon and 
dying away towards sunset. Sometimes it blew so strongly 
when I was on Damba that canoes could not go out on 
account of the white capped waves and the surf on the 
shore. If this wind freshens again after sunset for a 
little while, it usually implies bad weather next day, 
especially if, during the night, a few fat drops of rain fall. 
Such a night followed by a very calm, clear, warm, clouded 
morning at daybreak invariably portends a storm before 
mid-day, and one would not think of going out in a canoe. 

On the contrary, an early morning cold northerly breeze 
from the mainland, with thick haze, foretells a very fine 
hot day. This north breeze blows quite violently until 
8 or 9 a.m., when it suddenly drops ; and, as suddenly, 
the south-east wind rises and impresses its mark on the 
lake before the waves due to the north wind have subsided ; 
so that one sees ripples travelling in a northerly direction 
superimposed on the swell running southwards. During 
the rainy season, when there is a calm, curious map- 
like areas of irregular shape and varied tints appear on 
the still water, and I came to the conclusion that they 
preceded a storm. 

Occasionally during this time of year the sun appears 
surrounded by a misty ring at a considerable distance 
from it ; but this was not common, and I never was able 
to make out that it heralded any particular type of weather. 

In the driest months at the end of one year and com- 
mencement of the next the sun's heat is powerful enough 
to cause grass to take light spontaneously. Fires seen 
on the islands are usually considered to be evidence of 
the presence of natives in the forbidden area, but I am 
quite satisfied, from the following instance, that they 
can be of " spontaneous " origin 

On January 29, 1919, I was examining Nyenda Island, 



SPONTANEOUS GRASS FIRE 77 

my camp being on the southern side of Wema. As we 
returned in the afternoon the grass all round the camp 
was seen to be burning, and I found when I got back 
to camp that it had had a narrow escape. The boys 
said that about 2 p.m., while in their houses,' they had 
heard a sound like a gun-shot, and going out, saw a 
cloud of smoke arising to windward, and heard flames 
crackling. They only just had time enough to strike the 
tent and get my things further away from the edge of the 
long grass, and had there not been a space cleared for 
the camp, the huts would all have been burnt. 

They showed me afterwards the spot where the fire 
had commenced. Among much bare red rock there was 
thin dry grass on light soil, and at one place was a hole 
looking as if the earth had fallen in over a termite's 
burrow. Here was an appearance that suggested that a 
quantity of dry debris lying at the bottom of the open pit 
had suddenly taken fire with explosive violence, for the 
edges of the hole had obviously just been disturbed. 

Such fires are well known to the natives, who call one 
" Nakibengeyi " ; they pointed out the red rock to me 
as a kind that is particularly associated with these 
spontaneous fires. It is of a spongy texture, apparently 
of igneous origin, and certainly does absorb and radiate 
a great amount of heat from the sun. 

The signs of weather afforded by the island life are 
abundant, and doubtless many more than here recorded. 
Several birds give useful indications. A curious booming, 
hollow sound is sometimes heard during the rainy season 
preceding a storm, and it was a long while before I finally 
satisfied myself that it emanated from the crowned 
crane. The natives insisted that it was produced by the 
puff adder ! 

The large black and white hornbill is always much 
more vociferous on one of the clear blue evenings before 
rain, and gulls on the rocks scream and chatter much 



78 THE LAKE 

more vigorously. When terns appear off the coasts of 
islands, one knows that windy weather is coming, for 
under other conditions they were never seen ; presumably 
they then frequent the open lake. 

The glorious fish eagle is much more vociferous, accord- 
ing to the natives, when the wind is rough, but I never 
satisfied myself of this, and think he screams more on 
account of brilliantly fine weather, which, of course, is 
often accompanied by a fresh breeze. One of the large, 
pale blue, insectivorous kingfishers, which haunts thick 
bush or forest, utters his characteristic cheerful cry with 
greater persistence when the early morning is particularly 
fine and brilliant. A species of woodpecker, like the 
" yaffle " at home, is only heard to cry before rain. 

Frogs, . of course, croak before rain, especially one 
species which inhabits burrows in the earth ; indeed, 
it is never heard to croak except in the evening, before 
rain, unless it is breeding. The green tree-frog, so 
abundant on herbage of the lake shore, sends forth its 
high-pitched, scraping note when it thinks there is 
rain about. 

I had an amusing experience one day on the shore. 
It was about noon on a very fine day ; a small cumulus 
cloud slowly formed and emitted a single crack of thunder 
without in any way dimming the brightness of the day. 
This clap of thunder was immediately followed by a chorus 
of satisfied quackings from a host of concealed frogs, 
sounding ridiculously like applause of a well-meant effort ! 
There was no rain, however, so the prophets were 
forsworn. 

Fish also afford signs for a weather prophet to interpret. 
Thus, in my journal for January 30, 1914, is noted : 
" Off the south-west point of Ngamba Island little fish 
were leaping about in the water and also in shore, close 
under the bushes. About a hundred yards away from the 
island the glassy surface of the water was broken by a 




AERIAL ROOTS DH'I'ING TO GROUND, BUGALLA FOREST. 




GIANT TWISTED STEM OF CREEPER, BUGALLA FOREST. 



To face p. 78. 



WEATHER PROPHETS 70 

collection of the ' male ' fish (see Chapter IX, ]). 193) 
tumbling and wriggling about. The natives said they 
were mating." The next day was noted as " a beastly 
cold, stormy day, with black clouds, after a lot of thunder 
and rain at 1 a.m." On Feburary 21st the same occur- 
rence was seen off Wema Island ; the small fish hopping 
out of the water, and male tumbling about. The 
following day, however, was also fine and hot, and rain 
did not come until the twenty-third. 

I think this behaviour of the fish is not of any immediate 
significance, but occurs just before the rains commence 
in earnest, in March. 

It was again noticed very often when voyaging in 
January and February 1919 ; sometimes the canoe 
would be so close that the men could almost have netted 
the fish. 

Insects, as might be expected, furnish many signs of 
coming rain. 

The most obvious is the appearance of immense numbers 
of a non-biting gnat, of the family Chironomidae, called 
by the natives " E'sami " (pronounced Sammee). They 
appear as brown clouds drifting over the lake, along the 
horizon, like smoke from a distant steamer. Eventually 
they are blown ashore, where they seek shelter among 
trees. These clouds are most often seen just before 
and during the heavy rains. If Sami happen to arrive 
at one's camp after dark they swarm around the lamp and 
drive one nearly desperate. Other insects also come to 
the lamp before rain, particularly Ephemeridae of different 
sizes. One, about the size of the common English " may- 
fly," once came to the camp fire in such numbers, anS 
their burnt bodies made such an appalling stench, that 
it was too much even for the natives, who put out the 
fire and retreated ! A smaller, paler species has the 
extremely annoying habit of alighting upside down on 
one's table or writing paper, and flopping miserably about 



80 THE LAKE 

until he dies ! Other still smaller species of two-winged 
flies have an extraordinary liking for singing their high- 
pitched song inside one's ears, until one can bear it no 
longer and retires beneath the mosquito net. 

To these nuisances may be added an enormous male 
ant {Dorylus) with shiny, hard, light brown body over an 
inch long, who bangs himself against the lamp, and returns 
however often he be thrown outside with contumely, 
until one is forced to go against one's scruples, and bottle 
him. I have dispatched as many as twenty on one evening. 
They are a very reliable sign of coming rain if they are 
seen in any number : the workers also are much more 
often seen on the march before rainy weather. Termites, 
likewise, are much more harmful in wet weather, and 
cover the timbers of one's house with earth with sur- 
prising rapidity at such times. 

The biting flies known as " buffalo gnats " (Simulium) 
are especially eager to bite in the early morning or evening 
before rain on the islands. Thus on July 26, 1914, 
on Kome Island, is noted in my journal : " I went down 
to the rocky shore before breakfast, and was set upon by 
a swarm of viciously biting Simulium. In the evening 
many Ephemeridae came to the lamp." Next morning, 
after daybreak, there was the worst thunderstorm I 
had ever experienced on Kome. 

The night time on the islands, apart from thunder- 
storms, has charms of its own, A number of sounds 
are to be heard from sunset until the small hours, when 
for a while there is silence until the first glimmerings of 
dawn. The thunderous snortings of hippos, the muffled 
bark of the Situtunga, break in upon the continuous shrill 
tinkling sound, curiously suggesting sleigh bells, produced 
by thousands of small frogs along the shore. Crickets 
chirp all round and in the house, and during the rains one 
enormous species, sitting just inside the mouth of its 
burrow, makes the earth resound with a continuous high- 



BIRD SOUNDS 81 

pitched buzzing sound, which if at all near seems to 
penetrate through and through one's head, and renders 
sleep impossible until the performer has been silenced. 

The chattering and quarrelling of gulls on the rocks 
mingles with the plashing of wavelets and the gaggling 
of Egyptian geese, which are restless at night. 

Perhaps there passes overhead a flight of some kind of 
plover, whose cry has earned for them the native name 
" Empunya," and in the distance, over the open grass 
land, a hunting owl emits its drawn out quavering call, 
and a nightjar its " Tok-tok-tok-tok-tok " for long periods 
without a pause. 

Occasionally an ibis, startled by something, disturbs 
the night with its raucous alarm cry, " Aa-aa-aa," or an 
awakened monkey in the forest says what it thinks of 
the disturber before settling down to sleep again. 

With the first glimmerings of day the chorus of birds 
begins, and the forest resounds with their cries and music, 
for there are many songsters of merit. Soon the troops 
of monkeys awake and commence their hunting, and the 
loud " kubba-kubba " cry shows where they travel among 
the tree-tops ; and for the rest of the day the forest is 
never silent. A species of forest francolin, living in the 
densest thickets, has a loud ringing, laughing cry which, 
taken up by one after the other, often resounds through 
the forest during the heat of the day when other birds 
are relatively quiet. Towards evening the hornbill 
waxes vociferous, and his " Nga-nga " cry, from which 
he gets his name, seems characteristic of that time ; 
flocks of grey parrots flying home from the forest shriek 
in the familiar discordant way, and snow white egrets 
sedately wend their way with hoarse croakings across 
the blue water to their accustomed roosting places. The 
sunset chorus of songsters has hardly subsided before 
the frogs and crickets take up the strain, and with the 
rising of the moon owls add their melodious cry. 

7 



82 THE LAKE 

Life on the islands was soon reduced to a routine only- 
interfered with by the weather. Arising shortly before 
the sun one pottered about for half an hour before a 
bath, or a swim, and breakfast. 

At eight o'clock one set off for the fly ground. On 
Bugalla this simply meant a walk of about half a mile 
down from the open grass clad hill on which camp was 
placed, through the forest belt, and out on to the sandy 
beach. 

When on Damba we cut across a shallow bay by canoe 
to the beach about a mile away ; from Kome camp we 
went by canoe to the other islets, and very pleasant going 
it was against the fresh north breeze and dancing waves, 
taking an hour or more. From this one returned at any 
hour between 2-5'30 p.m., after which there was a certain 
amount of work to be done with the microscope. 

On Bugalla the afternoon was always spent over the 
microscope ; and a walk over the highlands in the evening 
gave one exercise and beautiful views. 

Sundays were always given up to butterfly hunting 
and other changes of occupation. On Saturdays the big 
canoe with crew of fourteen men started off for Entebbe 
taking mails, returning on Tuesdays or Wednesdays 
according to weather, with mails and the week's supply 
of food for those of us who always remained in camp. 
Sometimes this canoe had very rough passages, and I 
well remember one night near the end of my residence 
on Bugalla. It was one of the exceptional occasions when 
there was a storm after sunset coming from the north- 
east. The crew as usual had announced their approach 
by blowing on a horn of the Situtunga antelope, and I 
was rather anxious, as a storm was threatening from the 
same direction. 

Gradually the wind freshened until a gale was blowing, 
and the house rocked. I lit a lantern and went down 
to the shore to mark the landing place, as it was pitch 



AN UNUSUAL STORM 83 

dark. Above the roar of the surf on the coast could be 
heard the shouts of the paddlers furiously urging on the 
canoe in front of the storm, but they were not able to make 
the shore where I was on account of breakers. By great 
good fortune they were enabled safely to round a headland 
and land in comparative calm. Had the storm been from 
the usual south-east direction, they could not have faced 
it, but would have had to turn and run before it ; but 
these early night storms came from a direction different 
from that of the formal storms described previously. 



CHAPTER V 

CANOES AND A VOYAGE 

Unless one is very fond of the water and a good sailor, 
travelling by canoe becomes tedious or even unpleasant. 
If merely a passenger one sits right forward in the bows 
and, when the lake is anything else than smooth, very 
soon gets well splashed. I always took the steering 
paddle and found it great fun ; a good deal of skill is 
required to keep a heavy canoe true to its course when a 
strong beam wind persistently blows the bows round. 

The canoe (" Eryato ") made by the Basesse is of a 
peculiarly interesting type, since in the first place it forms 
a link between a " dug-out " and a built vessel, and in 
the second place shows how the keel of a modern boat 
represents all that is left of an original dug-out. ^ In the 
old days of warfare on the lake between the Basesse of 
the islands and the Baganda of the mainland, these canoes 
were of very large size, and I have heard it said that they 
could accommodate fifty paddlers. 

The most important part is the keel (" Omugongo "), 
which is hewn from a tree of a particular species, found 
by experience to provide the best wood for the purpose. 
It is very thick and solid, with a rounded bottom and 
hollowed-out upper surface, so that in transverse section 
it is concavo-convex ; it is, in other words, a " dug- 
out." Seen from above, it is broader in the middle than 
at the ends. 

^ Mr. Henry Balfour pointed this out when I gave him a model for 
the Pitt Rivers collection at Oxford. 

84 



STRUCTURE OF A CANOE 85 

The after end is ^shaped so that the stern post 
(" Ekiwenda ") can be fitted to it, and, similarly, a stem 
post is fitted near to tJie forward end of the hollowed-out 
keel, of which the extreme anterior pointed end has been 
left solid, to project beyond the stem post. 

These stem and stern posts are inclined forward and 
aft at half a right angle, and are fastened at the bottom 
to the keel, whose hollow is shaped to embrace them 
slightly by palm fibre passed through holes (" Endagire ") 
bored with a hot iron. The next step is the fitting of the 
lower side planks (" Amabasi "), one on each side, stretching 
from stem post to stern post, and secured to them and the 
keel by palm fibre {" Ensinga "). These planks are made 
from wood different from that chosen for the keel ; the 
latter has to be rigid, but a measure of pliability is required 
for the planks. The upper edge of the lower plank is 
neatly bevelled off to fit the lower edge of the upper plank 
(" Olwero "). This, again of a different wood, for it has 
to stand exjjosure to hot sun in between occasional wetting 
by waves without cracking, is made of three pieces, for 
it has to take a considerable curve. The main piece runs 
along the greater length of the canoe, but a small length 
(" Eryungo ") is required at bow and stern to take the 
curvature from the end of the main piece to stem or stern 
post. Where these pieces overlap they are neatly fined 
down so that the thickness of the two is no greater than 
the thickness of a single piece. At the extreme ends, 
bow and stern, the pieces of opposite sides are firmly 
pulled together by stout lashings passing across and across 
the interior of the canoe. The lines of junction 
(" Entabiro ") between upper and lower side planks, 
and lower planks and keel, are covered by laths of wood 
cut by spHtting sticks longitudinally ; a strip (" Olu- 
wamba ") is laid with flat surface next the junction, 
and lashings of " Ensinga " pass through the planks on 
each side of It, and over its rounded surface. 



86 CANOES AND A VOYAGE 

These strips cover the lines of junction on inner and 
outer surfaces of the canoe, and all crevices are thoroughly 
plugged with fibrous material. 

The thwarts (" Amanga ") on which the paddlers sit 
are fastened in a peculiarly ingenious manner, so that they 
also serve to brace the sides. 

Each rests on the upper margin of the lower side plank, 
which is notched to receive it, as is also the lower margin 
of the plank above ; the thwart itself is grooved, not 
quite at the extremity, so that its actual end is visible 
as a knob (" Empumi ") on the outside of the canoe. 
The grooves in the thwart and notches in the planks all 
correspond, so that everything fits as closely as possible, 
and leakage is prevented by plugging. All the holes 
through which pass the fibres fastening the planks are 
tightly plugged, and as the plugging swells in the water 
a good canoe leaks very little, although no resinous or 
tarry material of any kind is used. 

A peculiarity of these canoes is that right forward a 
long spike projects out from each side, made by a thwart 
(" E 'garni ") fitted exactly as are the paddlers' seats, 
with which it is serially homologous ; but its outer ends 
are produced into spikes instead of being rounded off 
into mere knobs. This projection is of great use when a 
heavy canoe has to be hauled up on the shore, but I do 
not know if that is why it was designed in the first place. 

Another feature is the upturned prow (" Ensanda "). 
It was said that the part of the keel left projecting beyond 
the stem post is not hollowed out, and gradually tapers 
off. Over this is fitted one arm of a large right-angled 
piece of wood, whose other arm therefore projects 
upwards into the air for two or three feet, and several 
feet forward of the real bow of the canoe, and makes an 
excellent breakwater against waves. The projecting keel 
gives an extra lift to the bow of the canoe, so that they 
are excellent sea boats, though the prominent prow and 







A CANOE RACE. 




A HALT ON THE EAST COAST OF KUGALLA. 



To face p. 86. 



FITTINGS OF A CANOE 87 

spikes manage to distribute a good deal of water over 
any one in the bows, unless there is a calm. 

On top of the " Ensanda " is placed a decorative tuft 
of feathers, known as " Enkuli," and a string stretched 
between it and the top of the stem post (" Ekiwenda ") 
has a series of plaits dangling from it vertically. This 
ornament is called " Akasenso." The top of the stern 
post is often also ornamented with a tuft of grass 
("Engudi"). 

When the canoe is sufficiently loaded, the ends of 
the thwarts are just on the water line. The paddles 
(" Enkasi ") are quite simply made, with no attempt at 
decoration ; the blade is broad at the base and tapers 
to a point, its surfaces not being absolutely plane, for one 
side ^s very slightly concave, the other equally slightly 
convex.' An essential part of the equipment of a canoe 
is the baler (" Olutiba "), made by hollowing out a 
rectangular block of wood into a shallow basin. One of 
the crew amidships makes it his business to free the canoe 
at intervals from the water that collects in the hollow of 
the keel (" Ekyuwo ") ; if the canoe is an old one so that 
the edges of the planks and keel are getting soft, it cannot 
be properly plugged, and one man is needed to bale con- 
tinuously. 

After two or three years the wood of the keel rots and 
the planks crack, so that the life of the canoe is finished ; 
the natives require two or three months to make a new 
one. 

With a good crew, each accustomed always to take the 
same thwart, and paddling well together to a rhythmic 
song, the motion is very pleasant, and considerable speed 
is attained. Sometimes each man, at the height of the 
stroke, knocks the haft of his paddle against the side 
of the canoe, and a good test of whether the men are well 
together is afforded by the noise : it should be as sharp 
and well defined as the rattle of eight oars in the rowlocks, 



88 CANOES AND A VOYAGE 

and a paddler who is very much out of time with the 
rest of the crew is greeted with yells of derision. 

The time is set by the two bow paddlers (" Balambi "), 
usually picked men. In my big canoe one was nearly 
blind from smallpox ; he was a native of the Sesse Isles, 
as are all the best canoe men. 

The steersman (" Omugoba ") also is one of the best 
paddlers, and in a high beam wind has all his work cut 
out to prevent the canoe from falling off her course, as 
I have often experienced ! For any slight correction 
he uses a peculiar stroke ; putting the paddle into the 
v/ater as far away from the canoe as he can reach, with 
powerful jerking movements, all his body and arms rigid, 
he pulls the paddle through the water towards him with 
a succession of rapid strokes. In a very heavy wind and 
sea, however, with a large canoe, this may not be sufficient, 
and the steersman then has to make a rudder of his paddle 
by using the projecting end of the thwart (" Empumi ") 
as a fulcrum, whereby great leverage can be obtained. 
The bowmen also help to pull the canoe's head round 
into the proper course by putting the paddle well away 
from the canoe and making the stroke towards the canoe, 
on whichever side it is necessary. 

On March 1, 1913, I started off on a "joy ride " to 
see Nkosi, the southernmost isle of all the Sesse group, 
which I had long wanted to see. The party consisted of 
twelve paddlers, three boys and myself, with food for 
four days and camp equipment in one canoe. At 7' 30 w^e 
got away, on a glorious, calm, sunny morning, in good 
spirits at the prospect of a change after over a year spent 
in the same camp on Bugalla. As we passed the north- 
east cape of Bugalla there was a fine Situtunga buck on 
the crest of the hill, but I could not see its horns, which 
the men said were of a good size. We w^ent southwards 
down the channel between Bugalla and Bunyama, and 
it was so calm that one saw well the lung fish that came 








PITCHING CAMP ON THE ISTHiMUS OF KIRUGU ISLK. 




"'^m ■ 



THE \Vi;>TEKN POINT OF KIRUGU ISLE AND THE ISTHMUS CONNECTING IT 
WITH THE CENTRAL RIDGE. 

To face p. 8 



A VOYAGE TO KIllUGU 89 

up to the surface for a breath of air. They put their 
mouths right out of water for a second or two, and then 
turn on one side and go down with a peculiar roll, nearly 
always flourishing one of the filamentous pectoral fins out 
of the water. 

Bunyama sends out a long point of rushes towards 
Bugalla, so that the channel is very constricted, and the 
scenery extremely beautiful. Bugalla here rises steeply 
from the water, the slopes being forest clad, as is the coast 
of Bunyama. Having passed this point we saw Fumvo 
in front of us, appearing as a steep grassy hill rising rather 
abrupt!}'' about 350 feet, with forest at its base. We 
went straight south between Bubembe and the prominent 
south-east peninsula of Bugalla, and then between Fumve 
and the little islet of Banda, off the bay on its west coast. 
Here the scenery was lovely ; the densely forested shore 
of Fumve was reflected in the blue glassy water of the 
bay, and Banda was like an enormous rockery. 

At 1 p.m. I thought a halt for lunch was indicated, 
^^s^s we had been going for five and a half hours, so we landed 
oijt'^he south end of Fumve and spent about an hour 
there. 

We then made straight for the northern end of Kirugu 
islet, which we reached after another two hours paddling. 
There was a lovely place for camping : a sandy isthmus 
well sheltered by trees under which the men could sleep, 
and providing an excellent place for the tent. This 
narrow neck joined on to the main part of the island a 
little plateau with cliff -like sides. The main part of the 
island is a long narrow ridge of grass, falling steeply to 
the water by cliffs or precipitous slopes, clothed by dense 
bushes and trees wherever they could cling : the island 
rises 180 feet above the water. 

Our choice of the sandy isthmus for camping was much 
resented by some hippos, who evidently had their resting 
places there, and grunted and snorted impatiently in the 



90 CANOES AND A VOYAGE 

water, whither they had been forced to retire on our 
arrival. Eggshells of crocodiles were scattered about 
over the sand, so that it was also a favourite resort, or 
at any rate a resting place, of these reptiles, but none 
were seen, which was fortunate, as a bathe in the clear 
water was found most refreshing in the evening. The 
little sandy neck was so narrow that one could choose 
calm or rough water to bathe in, according to the time 
of day. In the early morning the usual northerly land 
breeze blew, and the water on the south side of the neck 
was absolutely calm, to be ruffled during the heat of the 
day by the southerly wind. 

Next day I was awakened at 4 a.m. by the sound of 
waves breaking on the south side of the beach, the sign 
of a distant storm, which reached us about seven : the 
usual burst of thunder and heavy rain. At about nine 
the sky began to clear, and eventually the day became 
brilliant, but with such a steady strong wind that it was 
impossible to go anywhere in the canoe. I spent the 
morning taking photographs, and getting a view of the 
spacious distances from the top of the ridge of the island. 
The views were superb ; it was v/onderful to look south 
and see nothing but bluest water with white capped waves, 
and to think that there were ten score miles of it between 
oneself and the mainland. 

In the near distance lay Nkosi, the southernmost of 
all the isles of Sesse, and to the east the long high ridges 
of Kuye and Buguye,. with some smaller isles to the 
immediate west and north-west. 

In the evening the strength of the wind abated a little 
and the white caps were no longer seen, so that I was able 
to struggle down the more sheltered west side of the 
isle and see the waves breaking on the point, although the 
wind was still sufficiently strong to make it very hard 
work for both paddlers and myself steering. The sky at 
sunset was full of wind and promise of rain to come, 






'N KIKUGL' 1^LE. 




ON KIRIGU ISLE. 



To face p. 90 (first page). 



DOWN SOUTH TO NKOSI 91 

all the islands to the north being seen to stand out very 
sharply and clearly, and there being a thick smoky haze 
to south and west. 

Next day at sunrise huge masses of black thunder 
cloud were seen over Bugalla, which evidently was getting 
a heavy storm : our camp got a sharp squall at seven 
o'clock, which nearly blew the tent away and split to 
ribbons the outer fly. 

For a few minutes the rain fell in sheets, but soon passed, 
and by 8*30 a breeze cleared it up. The sun came out, 
and the day eventually turned out gloriously, with 
sufficient wind and waves to make the lake interesting. 
We had a stiff fight southwards against the breeze, and 
stopped for a brief rest among the pretty grottoes on 
the rocky fern clad islet Lukiusa, eventually reaching 
Nkosi at 10- 30. 

We first coasted along the south-east side, fully exposed 
to the breakers coming up from the open lake, so could 
not approach the shore very closely, especially as it was 
very rocky, and no risk could be run of staving in the canoe. 
Nkosi is a little over a mile long and a few hundred yards 
broad ; it is low, flat and bush covered, but the trees do 
not grow high, presumably owing to exposure to the 
constant winds from the lake. We rounded a tail of rocks 
at the south end, and got under the lea of the island into 
sheltered water, almost at once finding a most picturesque 
little grassy dell, with the lush green grass close cropped 
as if by rabbits. This was the work of Situtunga antelopes, 
of which one was soon seen quietly grazing. Their presence 
on this small, very isolated and exposed island is of 
considerable interest ; it is so covered with thick bush 
that open spaces are few and small, and they can only 
traverse the bush by definite paths. Since there can be 
no check on their increase save the amount of food 
available, disease and the physiological effects of in- 
breeding, the number on the island must long ago have 



92 CANOES AND A VOYAGE 

reached its maximum, and the pressure is presumably 
relieved by migration of the animals from Nkosi by 
swimming across to Buguye a.nd Kirugu Islands, and then 
by secondary dispersion to the large islands further 
north. 1 

It is an interesting problem how far this antelope can 
swim — for from the little islet Lukiusa, which could be 
used as a stepping-stone, it is at least two miles to the 
nearest neighbour, and open rough water has to be crossed. 

Even more interesting is the possible presence on Nkosi 
of a species of Cercopithecns monkey ; for as we gently 
drifted before the wind uj) the west side of the isle the 
voice of a monkey was heard among the trees. I much 
regret that I did not see the animal, for it is of course 
possible that the noise may have been made by a parrot, 
since I have certainly heard one imitate a monkey on 
Kisigalla Isle. 

The return journey from Nkosi to camp was easy, for 
wind and sea followed and helped us along, and I got 
back at 4*15 a.fter a most interesting dsby. 

Next morning it was calm and clouded, and we broke 
camp and got a^ay at 6- 45, having an uneventful run 
as far as Fumve, taking a course this time along the east 
coast, which is very picturesque. 

The whole side of the island forms a sort of huge 
amphitheatre backed by wooded slopes, and in the centre 
of the foreground rises extremely steeply from the water a 
flat topped, grassj'^ hill, almost as high as the rest of the 
island, about three hundred feet, making one think of a 
great altar in the centre of the amphitheatre. As we 
passed Fumve a thunderstorm came up behind us from 
the south-east, and I had to alter course, for it had been 
my intention to return along the east side of Bubembe, 

^ Major R. Meiiiertzhagen, F.Z.S., who visited Nkosi in one of the 
lake steaiTiers during thf war, estimated that there must be two hvmdred 
Situtniga on the island, and that they were sulficiently different from the 
Bugalla forms to bo called a sub-species. (See Chapter VII.) 




OUTH END OK NKOSE ISLE. 
Grass cropped by Situtunga. 




-CANOE SEEN " BOWS ON," KIRUGU ISLE. 



To face p. 92, 



BACK HOME 93 

pass between it and Bugaba, and then to the east of 
Bunyama. The rough weather, however, now made it 
impossible to pass along the exposed sides of the islands, 
and we had to turn westwards and run between Bwiggi 
and the north end of Fumve. 

As it was, we had quite sufficient wind and waves to 
make steering the canoe very hard work, for the wind 
coming from behind and on the side blew the canoe's 
head round, and it required continual effort to keep her 
more or less before the wind. 

However, when we had passed through the narrow 
channel between Bunyama and Bugalla we got into 
sheltered water and were able to land on Bunyama for 
a rest and lunch, mid- day. 

The storm soon passed, and the rest of the day was 
bright and sunny, and we eventually got home again at 
2 p.m., where I found that only j'o inch rain had fallen, 
showing that the storm was very local. 

We had made the return journey in very good time, 
having travelled about forty miles between 6-45 and 2, 
with half an hour's rest. 



CHAPTER VI 

A TOUR OF INVESTIGATION AMONG THE 
NORTHERN ISLANDS 

The tour now to be described was made with Fiske at 
the commencement of 1914, its object being a comparative 
investigation of the chain of islands lying parallel to the 
north coast of the lake, so far as could be done from 
Entebbe as a source of food supply. 

Besides our two selves and our four servants there 
were thirty-nine canoe men, nine fly boys, and a minor 
chief to act as headman, with his attendant. All these, 
with belongings, were stowed away in two large canoes 
and a small one holding five or six men only, which we 
subsequently found very useful. We left Entebbe at 
9*15 p.m. on January 12th, having chosen the night time 
because of the high wind during the day, which would 
have made heavy work of paddling with well-laden 
canoes. It was a beautifully calm moonlight night, and 
we reached BuLAGO at 2-15 a.m., and pitched camp there, 
as it was to be our base for some days. This is an 
interesting island of curious shape, having a long forest 
clad peninsula jutting out from the north-east corner, 
and a large bay on the north shore, along which is a belt 
of forest. The east coast is almost bare of trees or bushes, 
the west has a fringe of bush, and the south point ends 
in a sand-spit, much to the liking of crocodiles. Open 
grass land forms the centre of the island, and rather on 
the western side two rounded hills rise a couple of hundred 
feet. 

04 




BULAGO ISLE, NORTH BAY AND FORESTED NORTH POINT. 
Damba Isle on horizon. 




i 



THE OPEN GKA:,^ I AND INTERIOR OF BULAGO, WITH FOREST BEll A i 
SHORE OF NORTH BAY, AND ONE OF THE GRASSY HILLS. 



To face p. 94. 



BULAGO, KIZIMA 95 

We saw a good deal of Bulago, and studied it 
thoroughly, but found nothing very characteristic in its 
fauna or flora. A notable tree was one called by the 
natives " Musali," whose fruits were like loquats : I 
had seen small specimens of this on Bugalla, but here 
they were good-sized trees. 

A colony of the fossorial wasp Bembex was noted on 
crocodile point, where the sand was eminently suitable 
for their burrows. 

We had decided to take careful note of the butter- 
flies to be found on the several islands, as some sort 
of index to the general suitability of an island for 
insect life. 

On this first visit fifty-two species were noted, and on 
the return journey in March twenty-two more were added 
to the list. It was on Bulago that I first met with the 
Acraeine species Planema aganice and PI. alcinoe, neither 
of which occurred on Bugalla or Damba, though Damba's 
immediate neighbour Kome was subsequently found to 
have these interesting butterflies. 

On January 14th we visited the islet of Kizima. This 
is only about 300 yards in diameter, and rises out of the 
water as a rocky, flat topped, grass clad eminence, with 
shrubs and small trees along the steep coast line, and one 
little bay with sandy beach on the west. A tangle of 
" Oluzibaziba " bushes sheltered a hippo ; a large and a 
small crocodile and two large monitor lizards {Varanus, 
called " Enswa-swa " by the natives) were seen ; the 
basking places of the latter on the rocks were very 
numerous. 

Among the branches of a bush I found a small elapine 
snake, light grey with dark brown blotches, which had 
very obviously dined both wisely and well ! Rodents, 
about the size of a water vole, were abundant on this 
isle ; their runs were very noticeable, and also the debris 
of grass stems left where they had been feeding. Kizima 



96 A TOUR AMONG THE ISLANDS 

was therefore alluded to as a " rat island " ; several others 
will be described later. 

The little hill of Kizima seems to act as a chimney 
directing a continual current of air upwards, for whenever 
it v.'as visited there were always numbers of kites soaring 
round and round in narrow circles just over the island. 
Around it are fragments of rocks that have broken away 
and now form resting places for many cormorants and 
darters ; snow-white egrets with black bills and legs, 
Egyptian geese, and a giant heron were also there, with 
a sacred ibis, not to be seen on every island. 

Flycatchers were seen, and swallows were fairly plentiful. 

Butterflies were few (see p. 125) : Glossina was repre- 
sented by an average catch per fly boy of 29 per hour 
(both sexes). No termite hills were seen ; indeed, ter- 
mites seemed altogether absent. 

The Island of Tavu was first visited on January 
13th. It is about a mile in greatest diameter, being 
low and flat and covered thickly with vegetation. 
The northern two-thirds are marshy, and only ambatch 
grows there, with a dense fringe of rushes ; the southern 
end is very sandy and covered with cane, " E'tungulu," 
and bushes, with rushes growing in the shallow water. 
On the west coast is a large raised beach of sand, which 
was found to provide admirable breeding places for 
Glossina. The rest of the island has forest growth, and 
was at one time cultivated. Tavu proved to be a favourite 
haunt of crocodiles, of which nine were seen ; some on 
a rock on the east coast, others in the shallow water off 
the sandy south point, on which they lay their eggs. 
No " Enswa-swa " were seen, and subsequent visits 
always showed them to be scarce. 

Of snakes, the beautiful horned puff adder (Bitis 
nasicornis) was seen, and a large black elapine was rather 
common. 

Birds abounded ; giant herons, and herons of other 



TAVU— RESUVU 97 

species, glossy ibis, the open-billed stork, egrets and a 
stone curlew were seen, while cormorants and darters 
were numerous in the ambatch trees, on which they nest. 

In the thick jungle, where we very easily lost our sense 
of direction, the abundance of insect life was shown by 
bee-eaters, flycatchers, coucals and other insectivorous 
birds. 

Butterflies were numerous (see table, p. 125), and forest 
species such as Planema macarista, two species of Charaxes, 
and a large Euralia were noted. Three species of Tabanidae 
were noted on the shore, possibly the low lying and marshy 
ground is suitable for the larvae ; a common Tabanus 
{T. variatus), a Haematopota and Chrysops brucei were 
the species seen, the latter quite plentiful, and one was 
seen in the grip of a predaceous Asilid fly. Termites 
abounded, and the Dorylus ant was seen, while Culicine 
mosquitoes bit unpleasantly in the jungle. 

Large Achatina snails were plentiful. 

Olossina was very abundant, the island furnishing 
ideal conditions of food, shelter and breeding grounds. 
The average catch per boy hour was 39' 2. 

On January 17th I visited the sand bank south of 
Tavu, named Resuvu. Its north half is submerged at 
all times, and there is a dense growth of ambatch on 
which cormorants and darters nest. The south half, at 
this time, was above water, and measured about 50 by 
20 yards, but is probably almost entirely submerged when 
the lake level is high. Notwithstanding, I found larvae 
of a very common Noctuid moth ; in the sand a small 
black ant was found, and I saw a nest of the Belonogaster 
wasp, which feeds its larvae on caterpillars. 

On January 24:th we moved camp to Nsadzi Island, 
pausing on the way to examine Kimmi, which we found 
extremely interesting, since, though quite small and flat, 
it contains portions of almost every kind of condition met 
with on the lake shore. We landed first on the south- 

8 



98 A TOUR AMONG THE ISLANDS 

west side, whose eastern tip is formed of sand left by the 
receding lake at the foot of a low cliff in which are caves, 
full of bats. Further westwards the shore is low, of flat 
rocks, with many holes kept full of water by waves ; at 
a higher level is a sand beach now grown over by cane 
and bushes, and used as a nesting ground by crocodiles. 
The north-west shore is flat and marshj^ with a thick 
fringe of rushes and bushes of " E'tungulu " and ambatch ; 
the north-east part of the island is forested, but near the 
water is a large patch of open grass land, with very sandy 
soil, in which " Enswa-swa " burrow and lay their eggs. 
The south-east shore is marshy, with lush grass much 
frequented by hippos ; this type of shore was dubbed 
*' Hippo Grazing Ground." 

The vegetation of Kimmi seemed to me much more 
varied than on Tavu, which is about the same size. A 
Chrysophyllum tree (Sapotaceae), knoAvn to the Basesse as 
" Omugalati," which was not seen on either Bulago or 
Tavu, an anonaceous shrub scarce on the other two isles 
but abundant here, and a shrub with clusters of fragrant 
white flowers, which I had not seen before, were noted. 
Butterflies were fairly abundant, a forest Papilio, with 
several forest Planema, were noted ; the numbers counted 
will be found in the table (p. 125). 

The most striking feature of Kimmi was the vorac'ty 
of Glossina, which came off in a swarm to the canoe before 
we had touched land, and bit ferociously. It was found 
that more than half the number caught were females, 
which is quite exceptional ; the significance of this has 
been discussed in the chapter on Glossina. We comforted 
ourselves with the recollection that former experiments 
had never shown the flies from Kimmi to be infective, 
and put up with the inconvenience as best we could. 
The average catch per boy-hour for this island reached 
the high figure of 60* 9 : on one day alone it was 81 ! 

The hunger of the fly tallied with the fact that we found 



f 




a ^ 



NGAMBA 99 

no crocodiles or ** Enswa-swa," the favourite source of 
food ; although hippos are fond of the island I do not 
consider them of much importance as food for the fly, 
which has therefore to depend for food, on Kimmi, mainly 
on birds which frequent the shore. 

On January 30th we visited Ngamba, which lies between 
Kome and Nsadzi, This island, like Tavu, is covered 
with forest growth, but is more rocky and rises higher ; 
it is roughly square, and of about the same size as Kimmi. 
The forest everywhere comes close to the water's edge 
save on the east side, where part of the shore is marshy, 
and at the rocky north-east point. The shore, on the 
whole, is either rocky or pebbly, and only at the north- 
west corner is there a raised beach of sand. Along the 
south coast the rock is grey, but at the north-east 
point is of the more common spongy red brown 
formation. 

As usual we first circumnavigated the isle, and counted 
six crocodiles and three " Enswa-swa ; " two others were 
also seen, and bushes of " Oluzibaziba " bore evidence 
that Situtunga antelope had been browsing on them : 
probably these had swum across from Kome, where they 
live, for none were seen on Ngamba. The forest trees were 
noted to be varied ; one very fine fig tree with huge 
leaves, also occurring on Kimmi, was conspicuous here : 
the natives called it " Omululu." Another noticeable tree 
had sprays of greenish flowers like those of Portuguese 
laurel : the natives called it " Omuziru " ; and another, 
with large white flowers, was called " Omukoba." 

Here and there were beds of a magnificent herb which 
I took to be at least allied to Salvia, with spikes of large 
blue flowers, growing up to a height of four or five feet. 
This was subsequently often found growing in pebbly 
places near the water, and was quite a feature of some 
islands. Of birds, a sacred ibis and giant heron were 
noted, but no other notes were made. There were some 



/ 



100 A TOUR AMONG THE ISLANDS 

features of interest in the insect fauna : a D. chrysippus 
was seen crossing the channel betAveen Ngamba andNsadzi, 
and nests of the interesting ant (Ecophylla smaragdina, 
and the fierce 'little black ant called by the natives 
" Obusaji-saji," were found on leaves of trees ; they are 
not by any means universally distributed among the 
islands. 

The tubular cases of larvae of some species of Psychid 
moth were seen on the tree trunks in great numbers, and 
afforded the first example of the fact that a small circum- 
scribed area may support only a few species, but that some 
of these may flourish much more abundantly than in larger 
areas where they are exposed to greater competition. 
During the course of this tour many other examples were 
noted, and will be mentioned as instances of " insularity " 
in the fauna or flora. 

Glossina was scarce on Ngamba, the average catch being 
9" 9 per boy-hour. We remained at Nsadzi camp until 
February 5th, but spent only a little time over the island 
itself, since it was too big to be thoroughly investigated 
on a short visit. It is about three miles long, but very 
narrow : four-fifths consist of a steep grassy ridge almost 
bare of trees but with innumerable termite hills, closer 
together than I ever saw anywhere else. At the centre 
of the south side of the island cliffs descend steeply to a 
sandy bay, with a strip of forest at the foot of the cliffs. 
There is another patch of forest on the north side, but 
elsewhere the shore has only a very narrow fringe of bush. 
The eastern fifth of the island is low and flat, and sharply 
marked off by the escarpment of the end of the main 
ridge ; it is covered with forest, full of birds. On Nsadzi 
we found most interesting evidence of insularity. The 
grass on the uplands had been burnt off by Fiske on a 
previous visit some weeks before, and the new green blades 
were growing up among the burnt black stems of the 
tussocks. Over an area of a great many square yards 



^H 






■ 4 

M 1 


r| 


^1 

1 9 



NSADZI TO KOME 101 

every blade had been eaten by caterpillars of a Noctuid 
moth,^ whose green and black colours harmonized abso- 
lutely with those of the grass. These caterpillars were 
hurrying about in all directions looking for more food, 
and numbers of a brown " Ichneumon " were seen 
depositing eggs in them. While piercing the larva with 
its ovipositor the ichneumon grasped it firmly in its 
mandibles, a habit which is shared by the stinging fossors, 
who have adopted a somewhat more advanced kind of 
parasitism. 

On Nsadzi were found, firstly by Fiske, the footprints 
of a large Situtunga buck ; the importance of this has 
been alluded to in the chapter on Glossina. 

We moved from Nsadzi on February 5th to a new 
base on the east end of Kome, whence we intended to 
examine the small islands of that neighbourhood. 

It was a most lovely voyage on a calm and clear day, 
with much cloud of varied type and deep purple shadows. 
We left Nsadzi at 7 a.m., and travelled past the tips of 
the several peninsulae jutting out from the north shore of 
Kome, and then down the beautiful channel between 
Damba and Kome, where blue, pink and white water 
lilies were in full flower. A small cloud funnel was seen, 
giving warning of a short storm which came from 
the east at about 4 p.m., and burst on us while we were 
on Sanga Islet, but only lasted for half an hour. I was 
much interested in this, because while I had been encamped 
on Damba in 1911, only a few miles from Sanga, which 
could be plainly seen (see map), I had never had an 
afternoon storm there, but had noticed that the end of 
Kome often caught rain which missed my camp. 

Sanga Islet was examined this day, and was found to 
be amazingly interesting. It only measures about 100 
by 60 yards, is very rocky and well covered with forest, 
and shows abundant evidence of insularity. 

* Laphygma frtigiperda (Xenobianae). 



102 A TOUR AMONG THE ISLANDS 

The shore is composed of broken rocks, and the forest 
comes to the water, but there is very little undergrowth 
of bushes, so that we were able to walk about freely. 

Glossina was absent : the other arthropod life was of 
great interest. The first thing noticed was the abundance 
of very large, long-legged black and yellow spiders 
(Nephila), which spin webs several feet in diameter. 
These great webs formed sheets, often in planes one behind 
another when the branches offered suitable support, 
so closely placed that the spiders on the central sheets 
could hardly get any insects on their webs, and looked 
starved. Sanga, therefore, was known as a " spider 
island," and others will be described later. The next 
feature noted was the unusual abundance of predaceous 
Mantidae, and this was associated with absence of insecti- 
vorous birds ; a very interesting example of the " balance 
of nature." 

At the time of this visit, and we remained on the island 
several hours searching it thoroughly, I neither saw nor 
heard a single flycatcher, bee-eater, coucal, or any of 
the common small warblers ; parrots and weavers were 
the only birds noted in the forest. At a second visit, 
however, one " Kunguvu " flycatcher was noted, and the 
call of a common cuckoo was heard. Perhaps correlated 
with this absence of insectivorous birds was the fact, 
which Fiske and I noted independently, that the butter- 
flies, especially the mimetic Euralia and Aterica galene 
which I have always found very difficult to catch on account 
of their shyness, were here much less shy and easier to 
catch. Fiske thought that it was on account of the 
multitude of spiders' webs, which had resulted in the 
butterflies flying more slowly and cautiously to avoid 
them ; but I noticed that when on the ground the mimics 
were more easily approached than is usually the case. 

The numbers of butterflies found on Sanga are given in 
the table (p. 125) ; the most noteworthy feature was unusual 



SANGA— KISIGALLA 103 

abundance of the large Hesperid Rhopalocampta chalybe, 
whose peacock green and blue wings flashed in the sun as 
these beautiful butterflies darted about in the sunlight 
in typical " skipper " fashion. Acraeines were represented 
by two species among the tree tops out of reach, and one 
specimen of A. egina ; Amauris niavius was the only 
Danaine seen ; of Nymphalines, Euralia dubia, E. 
dinarcha, and a forest Charaxes were noted ; while the 
large and beautiful iridescent Salmnis, its pale green 
wings suffused with a pink mother of pearl lustre, was 
very plentiful. Lastly, the caterpillars of an aposematic 
moth, Aletis erici (see description, p. 214), were very 
abundant on Sanga, which interested me more than any 
other island, because it was the first visited of those on 
which the great spiders were so abundant, and showed 
so many other examples of insularity. 

On February 11th we visited the little isle Kisigalla, 
lying close to Sanga, and, like it, rocky and covered 
with trees, but with one piece of sandy shore. It is 
about fifty yards in diameter, and, though so close 
to Sanga, differs from it in many respects. It was 
characterized by almost entire absence of the Nephila 
spiders so abundant on Sanga ; by abundance of a large 
black Scoliid, of cocoons of the gregarious caterpillars of 
Lasiocampid and Eupterotid moths, and also of a very 
large fawn coloured slug. 

Birds were not so scarce as on the spider-haunted 
Sanga ; the " Kunguvu " flycatcher, sunbirds, weavers, 
pigeons, and the beautiful blue and crimson plaintain- 
eater were all noted. 

Butterflies were quite plentiful, the most interesting 
being the large mimetic Lycaenid Mimacraea poultoni, 
and the Nymphaline mimics Psevdacraea eurytus forms 
hobleyi and tirik^nsis. A very fine Satyrine that was new 
to me escaped capture. Glossina was scarce, the catch 
per boy-hour reaching only the average of 2-3. 



104 A TOUR AMONG THE ISLANDS 

The islet Lula, close to Kisigalla, was visited on the same 
day, and was found to differ considerably from its neigh- 
bour. It consists of a small rocky ridge covered by bushes 
and not by large trees, and is much frequented by crocodiles, 
whose basking places are numerous. Of birds, a black 
and white flycatcher, not met with on any other of the 
five islets off the east end of Kome, was noted to be 
relatively plentiful. Neither the spiders of Sanga nor 
the slugs of Kisigalla were found on Lula. Butterflies were 
interesting (see p. 125) ; Acraeines were more numerous 
than any other group, forming seven-fifteenths of the total 
number of species found; A. pentapolis was noteworthy, 
as it is not found on every isle. The Nymphalines were 
rather surprising : a huge Euralia, looking very out of 
place among bushes on a tiny islet, Pseudacraea eurytus 
form obscura, Ps. lucretia and Salamis made up the total. 
The only Lycaenid found was a brown, black spotted 
Pentila, whose Acraeine appearance fitted in well with the 
prevailing group of the island. 

Colonies of Eupterotid larvae were seen on Lula as on 
Kisigalla. 

The average catch of Glossina was 9* 1 per boy per hour. 

On February 6th we worked Dwanga Mkuru, the 
largest of three closely associated islands lying off the 
eastern point of Kome. This is about three miles long, 
and very narrow ; generally speaking, its features are 
of the type associated with a clear, rocky shore. 

The centre is a grass topped ridge sloping steeply on 
the east down to the rocky or pebbly shore, where at one 
point a dyke of red, spongy volcanic rock, stuffed with 
fragments of grey rock as a pudding is stuffed with plums, 
runs out across the pebbly beach. On the west side is a 
bold cliff, at the sheltered foot of which is a strip of thick 
fertile forest, with some huge " Omuvule " (African teak) 
trees, and an overgrown banana plantation. All along 
the shore on the east are thick beds of fern and Salvia, 



DWANGA MKURU AND MTO 105 

backed by thin and poor looking forest trees, swept by 
the prevailing south-east winds. Many of them were 
covered with spiders' webs, for this island is markedly a 
" spider island " ; as on Sanga, this is correlated with 
great scarcity of insectivorous birds and abundance of 
Mantidae. 

Butterflies were extremely abundant : the beautiful 
green, pinkly iridescent Salamis was more numerous 
than at any other locality visited, four might be 
seen at once. Of Acraeines, Planema poggei was of 
interest, and other Nymphalines besides Salamis were 
Euralia duhia and Pseudacraea hicretia, which latter 
Fiske, until it had been caught, thought must be a 
Neptis from its flight. I had often noticed that its 
flight was much more like that of a Neptis than the 
Danaine (Amauris), which it somewhat resembles in 
pattern. 

Glossina was completely absent from Dwanga Mkuru. 

DwANGA Mto, lying alongside the last named, was 
visited on February 9th. It is more or less covered by 
jungle, but there are some open patches, and it does not 
rise so high as its larger neighbour. The shores are mostly 
of pebble or rock, with much fern and Salvia, and the 
usual common bushes. 

A species of bush was seen by the water which had not 
been met with before ; it had very large heart shaped 
leaves and spikes of inconspicuous flowers : the natives 
called it " Omukwakula." Other features of the flora 
were a single specimen of the large " Ekibo " palm and a 
small patch of elephant grass (" Ekisagazi "), which is 
very unusual on the small islands. 

Birds were not so noticeably scarce as on Dwanga 
Mkuru, for sunbirds and bulbuls were plentiful and the 
" Kunguvu " flycatcher was there. 

Being markedly a " spider island," Dwanga Mto had 
abundant Mantidae; the large grasshopper called "E'jansi" 



106 A TOUR AMONG THE ISLANDS 

by the natives was much more plentiful than on other 
islands hitherto visited. 

Regarding butterflies, the most noteworthy feature was 
the abundance of the large Hesperid Rhopalocampta 
forestall, hitherto not encountered on the small islands ; 
its near ally, the beautiful Rh. chalybe of Sanga Isle, was 
not seen here. The single Papilionine (see table, p. 125) 
was P. leonidas, whose Danaine model Meliyida petiverana 
was also seen. Acraeines were so extraordinarily scarce 
that I only caught one specimen, and only one other 
species was seen. Nymphalines included Salamis, which 
was very abundant, Pseudacraea eurytus forms hobleyi 
and terra, Ps. lucretia, Euralia dubia, two Charaxes, 
a Neptis, and H. misippus and C. cardui, neither of which 
occurred on other islets of this group. 

A curious Lycaenid was found here, a large grey species 
with angulated wings. ^ A feature of the island fauna was 
the number of long narrow cases of the larvae of a Psychid 
moth, attached to tree trunks. 

Glossina was almost absent ; the nine fly boys could only 
catch four males and a female. 

The third island of this group, Dwasendwe, was 
visited on February 10th. 

It is covered everywhere with forest or overgrown 
plantations ; almost everywhere the shores are rocky ; on 
the north-east there is a dense bank of ferns. The main 
insular feature of Dwasendwe was the great abundance 
of the Aletis larva first met with on Sanga ; these had 
defoliated the food plants over a large area. 

Of butterflies, Acraeines were again very scarce, one 
Planema and one small Acraea only were seen ; of Hes- 
peridae the large Gamia bucholzi, with mottled underside, 
was noted : a Lycaenid was found which was never met 
with on any other island, and was apparently associated 
with the '' Omukwakula" bushes on whose flowers it seemed 

^ Aslauga purpurascens, Lipteninae. 



■'>.vi:/i*i/;!>^ifcii^^ 



MAUNGWE 107 

to be ovipositing. Although this bush was abundant on 
the neighbouring island, Dwanga Mto, this Lycaenid had 
not been seen there.i It is a large white species 
with fine hair-like wavy lines on the under surface. On 
this island was found in a spider's web a second specimen 
of the West African Lycaenid, first caught on Dwanga 
Mto. Dwasendwe was markedly a " sj^ider island " ; and 
Glossina was absent. 

On February 13th we moved camp to Kerenge Isle, 
one of a group lying further eastwards. Fiske and I 
started at 6-30 with four paddlers in the small canoe, as 
we intended to visit sundry islets en route, leaving the big 
canoes with kit and men to find their more laborious way 
in their own time. 

At daybreak there were very threatening clouds, with 
thunder to the south-east, and it seemed as if we must 
get caught by a storm. The canoe men paddled furiously 
to get to our first islet, and the small canoe seemed to 
leap out of the water at every stroke, so that the un- 
fortunate Fiske in the bows got very splashed, as there 
was som^e swell from the distant storm. After one and a 
half hours' paddling for the distance of six miles, we safely 
arrived at Maungwe, a rock spit only about 80 by 30 
yards in size, thickly covered with ferns, herbs, low bushes 
and Ipomaea creepers with a few fig trees, on a fork of 
one of which was an enormous nest, possibly of a heron 
or a bird of prey. A very common weed, with 
dull mauve flowers (Erlangea tomentosa, called by the 
natives " Obutwatwa "), grew very tall and in dense 
masses which sheltered a small bird with the habits of a 
flycatcher, brown, with white throat and belly and brown 
chest, which was subsequently found on minute islets 
only, nearly always in masses of the " Obutwatwa." 
It had a very sweet voice, and its song resembled part of 
a nightingale's repertoire, so I dubbed it for reference 

^ Spalgis pilos. 



108 A TOUR AMONG THE ISLANDS 

sake " Nightingale flycatcher." Swallows and weavers 
feeding on the " Sami " gnats were also plentiful, and 
small lizards were seen. 

No Lepidoptera were notedj although a Belonogaster 
wasp was seen, which is known to feed its grubs on cater- 
pillars. Two species of carpenter bees which bore into 
wood, and small ants, were seen, but there were no Glossina 
on Maungwe. 

By the time we had finished with this little island 
all threatenings of storm had passed off, and we went 
on happily to Enkusa Islet, merely a reef of red spongy 
rock for the most part broken into pebbles, with a 
dense growth of ambatch bushes at one end, inhabited 
by weaver birds. There was a great growth of a large 
yellow vetch, 1 which seems to prefer pebble beaches in 
the vicinity of water. One small and feeble Lycaenid 
lived on this islet, keeping close to the ground. 

From Enkusa we went to Zmo, going round Isentwa 
and through a break in a reef which almost joins the two, 
into a very secluded bay dubbed by Fiske "the Pirates' 
Haven." Here we lunched, and afterwards went up on to 
the central grassy hill to get a broad idea of this island 
and its neighbours. 

The general appearance of this group was not at first 
sight inviting, after the beautiful, forested and friendly 
islands of the Kome group. They have grassy hills, but 
much less true forest growth : the pyramidal grass clad 
peak of Kiuwa was very striking, apparently rising straight 
out of the water, treeless, as high as the highest point of 
any island of the neighbourhood. 

We did no work on Ziro this day, but visited it subse- 
quently. The only notable feature about its coast is a 
rocky headland at the south-east point, with caves of 
weird fashioning quite suited for pirates' lairs ! 

I noted that the flora of the isle in some respects rather 

^ Crotalaria striata. 



ZIRO— SPIDERS' WEBS 109 

differed from that of the group we had just examined, 
for several flowers were seen that had not been previously 
noted but which had been noted at Jinja, on the main- 
land, in 1910. Two instances of butterflies similarly 
occurred ; and these facts suggested that these isles had 
not been connected with the former group, but only with 
that part of the coast immediately to the north of them, 
the others perhaps having derived their inhabitants from 
the mainland more to the west. (See map.) 

As regards birds, several giant herons, a dappled grey 
heron which I had not seen before, and open-billed storks 
in great numbers were seen. 

Flycatchers were seen and heard in fair number ; 
Enswa-swa lizards seemed fairly numerous, for nine were 
noted. 

Ziro is markedly a " spider island," but Mantidae were 
not noticeably abundant. Of butterflies, Acraeines were 
very abundant ; A. encedon in several forms was note- 
worthy, A Lycaenid^ was taken which I found at Jinja 
in 1910, but had riot been met with on any of the 
islands : this is notable after what has been said about 
the flora. 

Glossina was far from abundant, the average being 
6-8 per boy-hour. 

We remained in our camp on Kerenge from February 
13th-20th, using it as a base from which to visit neigh- 
bouring isles. There was nothing very characteristic 
about it ; it is flat and has a good deal of open grass land, 
and there are remains of former banana plantations, now 
full of the great spiders' webs to a disgusting degree : 
to get one's face and hat, or bare arms, covered with the 
sticky clinging web was extremely unpleasant. So strong 
is the silk that a sunbird was seen in a web, having become 
so entangled that it could not free itself ; we managed to 
reach up to it with a long stick and set it free. The webs 
* Lachnoenema bibulus. 



110 A TOUR AMONG THE ISLANDS 

were so close that the spiders on those between others 
were quite starved and their bodies very shrunken. 

Mantidae were not noticeably conspicuous ; the large 
" Amajansi " grasshoppers were, and the beautiful king- 
fishers which feed on them were also abundant. Acraeine 
butterflies were not so abundant as on Ziro, indeed here 
they were almost absent ; Lycaenidae were relatively so 
abundant as to be the main feature of the butterfly fauna. 
Of Hesperidae the large Gamia bucholzi was noted, and 
Fiske found a shady bank where large numbers of a 
Hesperid new to me were to be seen ; ^ it seemed to be 
associated with a plant, probably of the Arum family, 
which carpeted the ground here. Glossina only averaged 
62 per boy-hour. 

We visited Lukalu Isle on February 16th, and found it 
very interesting. About half a mile long, but narrower, 
its greater part is a grassy plateau rising slightly in the 
centre, with large beds of bracken on the slopes ; at the 
east end are some high rocks with caves, and here are a 
few big trees. One of these was like the common tree ^ 
called " Ekirikiti " by the Baganda, but the spiky flowers 
instead of being scarlet were of a rosy pink tint which I 
had not seen before. 

From the eastern end of the isle stretches along the 
south shore a narrow strip of dense bush ; the north shore, 
however, is very different, there being a belt of thick cane 
growing on sand, on which were marks showing that 
crocodiles had lain there, and hippos had made tunnels 
through the cane thicket. 

Five Enswa-swa were seen. The only birds that attracted 
attention were a coucal and a grey plaintain eater ; the 
" Kunguvu *' flycatcher was not seen. No Nephila spiders 
were seen ; of butterflies Lycaenidae predominated ; 
Lachnocnema bihulus was caught ; Acraea encedon was 
in great variety ; the only Nymphaline seen was Precis 

^ Andronymua lemider. - Erythrina tomentosa. 



LUKALU— ISENTWA 111 

clelia. Glossina averaged 10- 6 per boy-hour. There is a 
small accessory islet to the east of Lukalu, separated 
from the main isle by about 50 yards of water ; it measures 
about 100 by 50 yards, and is composed of red rock broken 
up into pebbles on its surface. There was a variety 
of flowering plants and low bushes at one end, and 
many ambatch trees, among which a species of moor- 
hen was noted. Weaver birds, sunbirds and wagtails 
were plentiful. 

The only butterflies noted on this accessory islet were 
the Lycaenid T. telicanus, which was evidently much 
attacked by wagtails, for a large proportion had a 
A -shaped piece taken symmetrically out of the two hind 
wings. 

On February 16th we visited Isentwa Isle, which is 
roughly triangular, having sides about three hundred 
yards long. 

It is composed almost entirely of grass land, with a 
narrow fringe of bush or cane at those parts of the coast 
where the rock is not too steep. Enswa-swa were noted 
abundantly, but no crocodiles were seen ; indeed, as a 
whole the islands of this group had very few crocodiles. 

Big spiders were absent from Isentwa, and also Glossina ; 
butterflies were very few, the feature being abundance 
of the woolly-legged Lycaenid Lachriocnema bibulus, of 
which at least half a dozen individuals arose together 
from one plant as I passed. The only Nymphaline seen 
was Precis archesia. 

KiuwA Island was visited on February 19th, and proved 
to be remarkably interesting from the point of view of 
the bionomics of Glossina, which was found to the extent 
of 18-2 per boy-hour, and yet we could not make out where 
were the pupae which kept the numbers at this level. 

Search as we would, no more than an average of 3* 3 
pupae could be found per boy-hour, in spite of rewards 
offered. 



112 A TOUR AMONG THE ISLANDS 

As has been said, the island consists mainly of a steeply 
rising grass-clad conical hill, a little over a mile long and 
half as broad ; its north-east end slopes less steeply, 
and here is evidence of former banana cultivation, the 
shambas now overgrown with bush and creepers ; some 
of the rose flowered " Ekirikiti " trees first noted on 
Lukalu were seen. There were also thick bushes of the 
usual kinds, and beds of the Salvia-\ike plant. Along the 
south-east shore are bold cliffs, at the foot of which are 
two little bays with beaches of pebble ; the south-west 
shore is formed of unbroken rocky strata rising steeply 
from deep water ; the west shore slopes less steeply and 
is fringed by bushes, so that, on the whole, the island 
seems unfavourable for Glossina, which yet was numerous. 
Three crocodiles and one Enswa-swa were seen, but no 
traces of hippo. Fruit eating bats were abundant, and 
small rodents were very numerous in the tussocky grass, 
so that Kiuwa was called a " rat island." 

In the old banana plantations sunbirds and weavers 
were very plentiful ; flycatchers were scarce, and none 
of the black and white species were seen. A thrush was 
heard singing, which, though plentiful at Entebbe on the 
mainland, I had never heard before on an island. 

Only one single specimen of Nephila spider was 
seen ; no termite hills were seen anywhere on the 
island. 1 

The butterflies of Kiuwa were rather interesting (see 
table, p. 125) ; three species of small brown Acraea were ex- 
tremely abundant, but encedon was not seen. Nymphalines 
were very scarce ; a Pierine scarcely ever met with on the 
islands was quite abundant on the beaches on the south- 
east shore ; two Lycaenids not common everywhere 
were noted as abundant ; Hesperidae were very scarce in 
individuals, and only four species were seen. 

On February 20th we moved camp from Kerenge to the 

^ Cp. Kizima, also a " rat island," 



ZIGUNGA— WEMA 118 

south side of Wema Isle, visiting Kibibi ew route, and also 
the Islet of Zigukga. 

This consists of two small islets joined by an isthmus, 
so that the south-west coast forms a bay : it is composed 
of red rock, covered with grass and rising steeply ; there 
are a few fig trees. 

A feature of the island was a plant with thick, sword 
shaped leaves, from which the natives obtain fibre. One 
crocodile and two Enswa-swa were seen. 

Swallows, weavers and sunbirds were quite common, 
and it was interesting to find again the " Nightingale 
flycatcher " frequenting thick clumps of the plant 
Erlangea (" Obutwatwa ") as it did on Maungwe Isle. 
No Nephila were found, nor were Glossina seen ; a single 
Acraea and a long-tailed Lycaenid, abundant on Kiuwa, 
were the only butterflies noted. 

After visiting Zigunga we went on to Wema, a large 
island on whose south shore our new camp was pitched, 
and used it as a base until March 2nd. It was much 
too big to be thoroughly examined in the time at our 
disposal, so we confined ourselves to the south shore. 

The views of Wema itself obtained from the summit of 
the hill behind the camp were quite the most beautiful 
of any I have seen on an island. 

There are four hills on the island, of which the one above 
alluded to, at the south-west corner, is grassy and flat 
topped ; another, at the north-west corner, is flat, with a 
patch of forest running nearly to the top ; on the con- 
necting ridge between these two is more forest, which 
also runs up the third hill, the central one of the isle, 
grass clad on top. The fourth hill at the north-east 
corner has a grassy base and a cap of forest on top. The 
south-east coast of the island has a fine fly beach with 
forest at the back, and the eastern point shows a red cliS 
visible from the camp. From the top of the hill behind 
the camp a lovely panoramic view was seen on the first 

9 



114 A TOUR AMONG THE ISLANDS 

evening ; looking eastwards across Yempata and Bus'ri 
one saw distant Buvuma, lying in the mouth of the gulf 
which gradually narrows down to the origin of the Nile at 
Jinja (see map) ; to the west, Damba lay long and low on 
the horizon, flooded with golden light from a lovely sunset. 

The part of Wema that was investigated proved most 
interesting ; Glossina was extremely abundant, averaging 
55 per boy-hour, and at one spot the catch averaged 101" 5 
per boy-hour ; one boy caught 78 in half an hour ! 

Monkeys were seen for the first time since we left Kome, 
and I was struck by the abundance of a black and white 
crow which flew about in flocks like rooks. Wema proved 
to be very markedly a "spider island," and as regards 
butterflies it was richer than any of the other islands 
investigated ; I think that it has probably as many 
species as the much larger Damba or Bugalla, and 
several Nymphalines were seen there which had not 
been met with on the larger isles. 

Of Papilioninae, P. dardanus and P. ugandae, with several 
other forest species, were noted ; also, P. leoyiidas and 
P. policenes were very common. Of Pierinae, several 
species of Terias and one Teracola were noted. The 
following species of Nymphalines were especially noted : 
Pseudacraea boisduvalli, lucretia, and eurytus forms hobleyi 
and tirikensis, six species of Neptis, together with Nepti- 
dopsis, nine of Charaxes ; Salamis was fairly abundant, 
while no Euralia was seen. Danaines were poorly repre- 
sented by a few D. chrysippus, Amauris echeria, A. niavius 
and yl, psyttalea. Only a few specimens of each were seen. 
Acraeines were surprisingly scarce ; very few individuals, 
belonging to nine species, were found ; noteworthy were 
Planema alcinoe, macarisfa and poggei. The Hesperidae 
included the peacock blue Rhopalocampta chalybe ; 
among the Lycaenidae was an extremely beautiful large 
blue species, with long tails of snowy white hue {Zeltus 
antif annus). 



MARIDA— WAVUZIWA 115 

Perhaps the most interesting butterfly of the islands 
was a Libythea caught by Fiske ; no species of this family 
had been met with previously on any isle. A total of 
124 species was found on this brief visit to Wema, and 
probably half as many again would be added by further 
investigation (see p. 125). 

On February 21st we visited two of the small islets 
Ijang east of Wema, going first to Marida, which consists 
of two flat, grassy portions connected by an isthmus 
along which is a pebbly beach. There is no forest growth, 
but low bushes and fig trees form a fringe along parts of 
the shore. A coniferous tree, Podocarpus, called by the 
Basesse " OmusSnene," was here noted for the first time. 
A crocodile was seen, and a nest of eggs found, and two 
Enswa-swa were found on the island. 

The only point noticed about bird life was that bee- 
eaters were there in some number, and they do not frequent 
every island ; sunbirds also were quite common on the 
isthmus, and the " Kunguvu " flycatcher was seen. 

Marida is very decidedly a " spider island " ; Glossina 
was represented by an average catch of 4*6 per. boy-hour. 
Of butterflies, it was remarkable that no Acraeines were 
seen, and while individuals of other species were scarce, 
a fair number of species was seen (see p. 125). 

The feature of Marida was the abundance of a slug, 
broadly resembling the English L. agrestis, but with a 
little fleshy spike on the end of the body reminding one 
of the caudal horn of a Sphingid larva ; this species had 
not been met with before. 

From Marida we went on to Wavuziwa, a rocky islet 
with very little shade except from fig trees ; ferns were 
abundant. One crocodile and one Enswa-swa were seen ; 
of birds, weavers and sunbirds were plentiful, also the 
" Nightingale flycatcher," and one coucal was seen. 

Glossina was very scarce, for all the fly boys together 
in an hour only caught seven ; Nephila was not seen at 



116 A TOUR AMONG THE ISLANDS 

all ; of butterflies, Acraea zetes, of rather Eastern type, 
was notable, and no Nymphalines were seen. Insular 
features of Wavuziwa were two ; a Lymantrid caterpillar 
new to me ^ was found in abundance feeding on the 
" Anyamberege " plant, on which plant I had never 
previously found any caterpillar, and fluffy white masses 
of some species of Coccidae, which thickly infested bushes 
and undergrowth. 

On February 26th, Sege was visited ; a not very 
interesting island of the same size as the last named, 
rocky, covered with grass and without any beach. Rather 
conspicuous on this islet was the fibrous leaved plant 
found previously on Zigunga, and an aloe whose spikes 
of scarlet blooms arose from rosettes of fleshy, thorny 
edged leaves. 

Two Enswa-swa were found on the island ; one, the 
biggest I ever saw, was much less timorous than usual, 
and did not retreat into the water until I approached 
within a few yards of it, after which it remained close at 
hand with its head above water. 

Of bird life the only notable feature was the " Nightingale 
flycatcher " ; Nephila was absent, Glossina very scarce, for 
the nine boys in an hour only caught twenty-seven, all 
males ; of butterflies, ten species were noted. 

Wait WE was visited on the 26th ; it has a central 
grass hill rising above the level of any of the neighbours, 
and sloping precipitously to the water on the west side. 
It is partly clothed with bracken, and the shores every- 
where are steep and rocky ; there is a fair variety of 
trees and, in contrast with Sege, abundance of ferns. 
Waitwe, like Kiuwa, is pre-eminently a " rat island," the 
tussocky grass being penetrated in all directions by their 
runs. Perhaps on account of this a small python was 
found on the island, in a cave. 

Three Enswa-swa were seen ; of birds, the " Kunguvu " 

1 Eucoma otricosta. 



YEMPATA lir 

flycatcher was present, and the familiar notes of a common 
bulbul made one realize that it had not been found on 
every island, Nephila was absent ; ten species of butter- 
flies were noted ; Olossina very scarce, for the nine boys 
only caught six in half an hour. 

On February 24th we visited Yempata Isle, going first 
to a minute accessory islet lying off its southern end. 
This was noteworthy by the scarcity of the " Oluzibaziba " 
bush ; there were some fig trees and, on the eastern side, 
" Ekinsambwe " bushes. No ferns were noted, but 
Ipomaea was abundant, and the whole centre of the islet 
was covered with masses of a thick leaved aromatic, 
labiate herb with spikes of purple flowers, and the mauve 
flowered " Obutwatwa " {Erlangea tomentosa), in which, 
as on other small islets, the sweet song of the 
" Nightingale flycatcher " was heard. 

Birds abounded on this islet ; on the rocks surrounding 
it were cormorants, gulls, egrets and giant heron ; moor- 
hens were among the bushes on the eastern shore, and 
many swallows and weaver birds were noted. Nephila 
and Glossina were absent ; the only butterfly was a 
Lycaenid ; bees were seen on the flowers. 

The main island of Yempata is rather flat, but there is a 
small amount of open grass land rising slightly at about 
the centre ; the rest is well covered with forest or the 
overgrown remains of former plantations. 

For at least half the length of the western shore there is 
a pebbly beach, backed by dense thickets of elephant 
grass (" Ekisagazi "), an unusual feature on any but the 
largest islands. The remainder of the west coast has a 
dense wall of bushes ; along the north coast there are 
rushes and papyrus, and on the east side papyrus, ambatch, 
and other bushes right up to the water's edge, forming 
excellent shelter for the Siibutunga antelope which the 
natives assert lives on the island. Along the southern 
shore is pebbly beach. 



118 A TOUR AMONG THE ISLANDS 

The old banana plantations bore evidence that monkeys 
live on YemjData, but thej^ were -not seen. Hippos, of 
course, visited Yempata, for old plantations are favourite 
resorts of theirs ; only one crocodile and one Enswa-swa 
were seen. Nothing is recorded in my journal about the 
birds of Yempata. Butterflies were numerous, but nothing 
of particular interest was seen, and in one visit to an island 
of this size no estimate could be made of their numbers. 
Nephila spiders were not seen ; Glossina was extremely 
abundant and as hungry as on Kimmi, and, as at Kimmi, 
came off to the canoe before we reached the shore. The 
average for the island was 67-6 per boy-hour ; but for 
the western beach only the figure was 79-5 ! 

On February 28th I visited Sindieo alone ; an island 
about the size of Bulago, with a low grassy hill at the 
north end and a rather flat southern point, the shores 
all round having a belt of very thick forest coming down 
like a wall almost to the edge of the water. In front of 
the forest are thickets of cane, e'tungulu and papyrus, 
in places so dense that landing was impossible, and we 
had to go round to the eastern side of the south point ; 
here w^e found a hippo pathway up which we crept 
ashore and found ourselves in a large open sandy space, 
in which were numerous burrows of Enswa-swa, presumably 
nesting places, as on Kimmi. 

Sindiro proved to be very decidedly a " spider island," 
and Glossina was represented by an average of 9-2 per boy- 
hour, in both of which respects this island shows interest- 
ing di£Eerences from its neighbour Yempata. Cicadas 
singing on the trees seemed to be more numerous than 
had been noted on other islands ; of butterflies, the 
Hesperidae seemed especially numerous in proportion to 
the rest. 

On March 2nd we moved camp, since food supplies were 
running low and Wema was too far from Entebbe for 
conveniently replenishing. So, to my regret, we left 




"-^-■^''■" 



KIBIBI 119 

beautiful Wema and returned to the former camp on 
Kerenge, visiting Kibibi en route. 

This island, about a mile square, was too big to be 
thoroughly examined in the time at our disposal ; it has 
a sugar-loaf, grassy hill rising to the usual height, and a 
good deal of park land with trees scattered singly or in 
clumps ; on the north point is some really beautiful old 
forest, which is bordered at the water's edge by the tallest 
thicket of Salvia that had been seen on the islands. 
Crocodiles and Enswa-swa were both scarce on Kibibi. 
Song thrushes were heard singing sweetly in some number, 
and the fine blue and red plaintain-eater (" Fulungu ") 
was noted ; this is usually not found on the smaller 
islands, though one was seen on Kiuwa. 

Only a single Nephila spider was seen. It was not 
possible to estimate the butterflies, but it was interesting 
to find a species of Byhlia^ which had not been seen on 
any other island, though it was found abundantly at 
Jinja on the mainland in 1910. 

On March 3rd, Kiuwa was again visited, and again 
worked very thoroughly without success in finding 
breeding grounds for the Glossina. I found three pupae, 
which were more than any one else found. 

On this visit was noted another butterfly which had not 
been seen since 1910 at Jinja, a very beautiful milky 
blue Lycaenid which was quite abundant. ^ Next day, 
owing to supplies having run very low, we returned 
westwards to a camp on the north shore of the large, 
flat, forested island of Damba. The camp was pitched in 
one of the few open spaces, and was memorable for the 
myriads of mosquitoes. 

En route we examined the Isle of Dyavodemu, lying 
in a bay near the mainland, and I visited it again on the 
6th. It is flat and without forest ; at one time it had been 
much cultivated, but the shambas were quite overgrown. 

^ See p. 109. - Castalius isis. 



120 A TOUR AMONG THE ISLANDS 

The shores generally are bordered by a thin growth of 
bushes ; on the south side is a pretty bay backed by a 
small cliff, at the foot of which bushes have apparently 
been used as a nesting place by egrets for many years. 
Birds were few on Dyavodemu ; no flycatchers, bee-eaters 
or coucals were found, and especially noteworthy was the 
complete absence of weavers, which had been found on 
almost all islands examined hitherto. 

Abundant on this island was a lizard which had not 
been seen in such number before : a short-legged, grey 
species, longitudinally striped, with a bluish tint at the 
base of the tail. 

Dyavodemu was emphatically a " spider island," not 
only the large Nephila being abundant, but also a smaller, 
reddish, thorny backed species with shorter legs being 
much more abundant than on other islands where it had 
been seen. Olossina was represented by an average of 
101 per boy-hour. 

Butterflies were interesting (see p. 125). Papilio demo- 
docus was seen ; Pierines were much more abundant in 
individuals than on other isles. Catopsilia and a Beleyiois 
were plentiful, and the latter could be seen in numbers 
crossing over from the mainland. Only two Nymphalines 
were found. Precis clelia and archesia ; Acraeines were 
abundant in species as well as individuals ; the most 
conspicuous, and so unusually plentiful as to be a feature 
of the fauna, was the rosy pink A. natalica pseudegina ; 
A. zetes was scarce, egina was not seen, encedon was in 
some variety. Of Danaines, only D. chrysippus was met 
with ; Lycaenids and Hesperids were few, both in species 
and individuals. Other insular features were the great 
numbers of Asilid flies, and of two species of beetles 
(Cassididae). It is possible that abundance of the 
predaceous flies, in the presence of multitudes of spiders, 
corresponded with abundance of Mantidae on other 
spider islands, for Mantidae were not found to be 
numerous on Dyavodemu. 



MTIOMU ISLET 121 

The beetles were on the Ipoinaea creeper, much of which 
was stripped of leaves by the activities of them and their 
larvae. One was brown in colour with rough surface ; ^ 
the other smooth light brown, with very variable and 
irregular black spots. ■^ 

On March 5th Fiske went to Entebbe on business, and 
planned to meet me with supplies at the old camp on 
Bulago on the 7th. 

I went to visit the small islets lying off the coast of 
Damba, close to the camp. The first, Mtiomu, of spongy 
brown rock, measures about 100 by 20 yards, and has a 
fine sand spit at the southern end ; in the water at the 
north end is a great grove of ambatch, which sheltered 
abundant cormorants and weavers. For such a small 
island the vegetation was extraordinarily varied ; except 
for " Oluzibaziba " all the familiar bushes and flowering 
plants of the lake shore were represented, so that several 
species of butterflies might have been expected ; but 
only T. telicanus, the cosmopolitan Lycaenid, was found. 
Sunbirds and wagtails were seen, and particularly interest- 
ing was the presence of the *' Nightingale flycatcher." A 
small brown lizard was very abundant. Nephila spiders 
were absent, also Olossina. 

Of Hymenoptera, several species of bees and Scoliidae were 
seen, and also the black and yellow Sceliphron spirifex. 

The insular feature of Mtiomu Islet was the great 
abundance of two large, conspicuous, aposematic beetles ; 
one a black and canary yellow species of Cetoniidae,^ 
evil smelling, and freely exposed on the flowers, the other 
a Longicorn,* black with transverse red bands, which 
fed on the green bark of sundry shrubs. 

Both of these are common insects, but were never 
found elsewhere in such numbers. 

The adjoining Islet Tokwi is much smaller, consisting 

^ Anpidomorpha near moufletti. ^ Aspidomorpha near signatipcnnis 
' Pachnoda sinuata. * Ceroplesis signata {Lamiidae). 



122 A TOUR AMONG THE ISLANDS 

merely of a few rocks and sand, with scanty vegetation. 
Except for one Enswa-swa and weaver birds and the 
" Nightingale flycatcher," there was little to note about 
the fauna. 

The tiny islet named Kawaga was visited next ; merely 
a flat topped rock about ten yards in diameter, rising 
sheer out of the water and about three feet above it. 
All round the edge grows the " Omuvuvumye " shrub, 
but nothing else save grass. Even this tiny islet had 
its entomological feature ; for, feeding on the leaves of 
the only kind of bush were great numbers of black larvae 
of a small Chrysomehd ^ beetle, brown and black. More 
interesting still was their complete absence from a pre- 
cisely similar but slightly smaller rock about twenty 
yards away, and from a third a little further away still. 
I visited Mtiomu again, but could not find any of these 
beetles or their larvae on the " Omuvuvumye " shrub there. 

On March 6th I visited Masovwi, a diminutive neighbour 
of Dyavodemu, which, measuring about 200 by 50 yards 
and lying very low, is formed of grey rock and has a good 
deal of sand on it. The southern shore is marshy, and 
fringed for half its length with a dense thicket of ambatch, 
the other half is open, with lush grass and flowers like a 
small sunflower. The centre of the island is piled with sand, 
on which grow thick bushes of " Ekinsambwe," and in 
which a batch of crocodile's eggs were found, the crocodile 
also being seen. On the whole, the vegetation was not 
varied, and there was no " Oluzibaziba." 

Birds were represented by a heron, many cormorants, 
and moorhens, with weavers, sunbirds and, since the islet 
was very small, the " Nightingale flycatcher." Nephilu was 
absent, and Olossina, rather to my surprise, was caught at 
the rate of 2*1 per boy-hour. Pupae were found, so that 
Masovwi is the smallest isle on which Glossina is known to 
breed. 

^ Mesoplatys ochroptcra. 



MOVING CAMP IN A STORM 123 

On March 7th I moved camp to Bulago ; the dawn 
was very stormy looking and there were spots of rain 
until 9 a.m. It then seemed as if danger of a storm was 
over, and I set off in the small canoe, heavily laden and 
low in the water, but hardly had we got well away from 
Damba when we were caught in a formal thunderstorm, 
coming, fortunately, more or less from astern. The small 
canoe plunged heavily and took a good deal of water over 
the bows, and it was necessary to shift some of the load 
further aft, rather a difficult procedure, as the canoe was 
full and far from steady. However, after this she 
rode better, and we proceeded on our way to Bulago, 
getting, of course, thoroughly soaked with the heavy 
rain. 

In the evening there was great dissatisfaction among 
the men on account of the small amount of food available, 
each man's portion being only about half a dozen bananas. 
While ruefully trjdng to make two and two into five, 
to my great relief I saw Fiske's canoe in the distance 
returning from Entebbe, and aU was well, for he brought 
abundant supplies and a huge mail. 

March 8th and 9th were occupied with work on Bulago, 
on March 10th we went to Tavu, and on the 1 1th to Kizima, 
where I heard the " Nightingale flycatcher," not previously 
noted there. 

The 12th- 15th were spent on Bulago, and on the 16th 
we moved to our former camp on Nsadzi, visiting Kimmi 
en route and working there again on the 17th. Ngamba 
was re-visited on the 18th, and Nsadzi itself was worked 
on the 19th. 

The results of these second visits to the above islands 
were most interesting, as the numbers of Glossiria were 
found to have greatly increased. 

On March 21st I visited Rumfua Island, which lies 
off the south coast of Kome. A rocky, bush covered 
isle, about half a mile long, but very narrow, the shore 



124 A TOUR AMONG THE ISLANDS 

formed of boulders, except for a shingle beach at the 
northern end. 

In the preliminary circumnavigation five Enswa-swa were 
seen, but no crocodiles. Rumfua is decidedly a " spider 
island," and the masses of their webs among the dense 
bush prevented one from walking over it. A great many 
hippo lairs were seen, so that the island seems to be a 
favourite sleeping place for them. Birds were scarce ; 
there were no weavers or sunbirds, and only one " Kung- 
uvu " flycatcher was seen. A large flock of egrets was 
noted on the shore. Egg capsules of Maniidae were 
particularly noticeable, though the insects themselves 
were not abundant at the time. 

The only butterflies noted were three Lycaenids and a 
Nymphaline, viz. the common T. telicanus and an equally 
common Lycaenesthes, and the rare Aphnaeus orcas ; the 
solitary Nymphaline was a fine Euralia. 

On March 22nd, with Fiske's departure, our joint tour 
came to an end. Apart from the results obtained bearing 
on the bionomics of Glossina, many extremely interesting 
facts had been noted regarding the predominance on 
certain islands of one or another type of insect ; and it 
was very interesting to see how, when the great spiders 
abounded, insectivorous birds were absent and the " balance 
of nature " was maintained by an abundance of Mantidae 
or Asilidae keeping down insects which might otherwise 
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CHAPTER VII 

MAMMALS 

The Hippopotamus. 

An animal of such large size as the hippo, called by the 
Baganda " Envubu," must naturally come before one's 
notice from time to time, but one really did not see much 
of him. My first acquaintance with him dates from 
Jinja in 1910, where a number could be seen in a large 
pool about a couple of miles down the river below the 
falls. The steep banks leading down to the river were 
scored by the constant passage of these heavy animals 
over the same track, until lanes had been worn in the soft 
soil several feet deep, of the width of the hippo's body, 
bearing an absurd resemblance to miniature Devonshire 
lanes. 

The bush on the banks was so thick that one could only 
get down to the water by using a hippo track, and wondered 
when so doing what a hippo would do if, when ascending, 
we happened to meet. For he certainly could not have 
turned. When on the islands one sometimes found the 
tunnels made through dense growth of reeds quite useful 
for getting about, though it was very fatiguing to walk 
half doubled up, and the soft mud was often unpleasantly 
odoriferous. 

During the day time the hippo spends his time resting 
in shallow water, or else sleeps in his favourite quarters, 
for he seems to be very much attached to particular 
places, and one would usually find a hippo off certain 

126 



NOISES— SLEEPING PLACES 127 

low lying peninsulae, among the rushes. When passing 
such resorts in a canoe the men always paddled very 
quickly, but my experience was that an unmolested 
hippo showed no resentment at being disturbed, and I 
never had any trouble and never shot at them. On the 
approach of the canoe the hippo would gradually sink 
until only the top of the head, with ears and eyes and the 
nostrils, were above water, when, in spite of the seeming 
absurdity, there was a certain horsiness about him ! He 
would watch the canoe suspiciously until it came too 
close, and then disappear altogether, when the canoe-men 
would paddle furiously until we were past what they 
considered a danger zone. When a frightened hippo 
comes up to breathe he expires the used up air with only 
a faint sound, but in the night their loud noises can be 
heard some miles away, and are probably used as 
a call. It is impossible to describe the noise, neither 
snorting nor grunting are completely descriptive ; it can 
be imitated by making a noise at the back of the throat 
while indrawing a breath. 

These calls at night have a fascination all their own ; 
sometimes, however, could be heard other much louder and 
less pleasing noises that seemed to indicate a battle royal, 
perhaps between rival suitors. 

Hippos have regular sleeping places in the forest or 
bush on the islands, from which they may sometimes be 
disturbed in the day time. 

On Kimmi Island, when with Fiske one day, I heard 
him say, " Well, isn't this just cunning," and, coming up, 
found hm looking at the sleeping places of a mother and 
baby hippo, where could plainly be seen the imprint of 
head, body and legs on the dead leaves, showing how they 
had slept side by side. The little rocky, bush covered 
islet Rumfua, of! the south coast of Kome Isle, was 
evidently a favourite dormitory, for there were several bed 
places among the thick bushes and ferns ; since there 



128 MAMMALS 

was nothing particularly tempting for them to eat they 
must have gone there expressly for sleeping. 

I once found among some reeds near the water's edge 
a well marked bed place, with a mud wallow beside it ; 
one was reminded of a house agent's advertisement, 
" bath room adjoining " ! 

Hippos wander about over the smallest islands ; thus, 
the central conical grass clad hill of Isentwa Isle, rising 
steeply from the water to a height of a hundred feet or 
more, had a definite track across the top ; but why they 
should visit an island apparently so unprofitable from a 
gastronomic point of view it is difficult to say. 

The wealth of vegetation that springs up in deserted 
banana plantations on the islands is very attractive to 
these animals, whose tracks always lead to the plant- 
ations. On a very sandy stretch of shore on Damba, 
I saw tracks of a large hippo with a baby, leading from 
the water into the forest, and quite close by were the same 
tracks leading back into the water. It was quite obvious 
that on the return journey the poor baby had been very 
tired, for when he got on to the soft sand he had not lifted 
his feet sufficiently to clear it, and a furrow between each 
footprint showed how his weary toes had dragged over the 
sand. However, he very soon got into the water for a 
rest. It was quite possibly this same mother that I saw 
one morning when on the way to the day's work on the 
fly beach. As the canoe drew near we saw, lying oflE 
shore, a large hippo lying on one flank in the water, with 
the whole of the other flank exposed. 

We naturally concluded it was a corpse, but as the 
canoe came nearer there was much difference of opinion 
among the men ; finally, when we came closer still, the 
hippo proved to be very much alive, for she rolled over 
and sank, and then we saw the heads of two babies also 
in the water. None of us had ever before seen a hippo 
take up this attitude in the water ; it seems possible 
that she was giving her babies milk. 



MOTHER AND BABY 129 

One day in January 1919, I went across to Damba fly 
beach from the east end of Kome Isle, but as a high wind 
had raised a considerable sea, it was necessary to find a 
sheltered spot for landing, and then walk round to the 
exposed beach, where the noise of the waves and of the 
wind in the belt of forest behind the beach drowned the 
sound of footsteps. Consequently a hippo mother with 
her baby that was sleeping in the forest did not take alarm 
at first. I was standing on the beach, observing the 
changes that had occurred since the last visit in 1914, 
when suddenly a loud snorting was heard, and the huge 
beast rushed past me into the water, closely followed by 
the tiniest baby hippo I had ever seen. It bleated in a 
most comical manner, rather reminding one of a toy, 
and was so small that it was still quite weak, and stumbled 
on to its knees several times before it reached the water. 
Though so young it was not pink, but dark brownish 
grey. I was so taken by surprise by their sudden 
appearance that the chance of catching the baby was lost : 
but it remained in shallow water just beyond the breaking 
waves, putting up its nose at short intervals for a breath 
of air. The mother was further away, evidently rather 
anxiously watching the fate of her little one, and though 
the boys with me wanted to go into the water and catch 
the baby, I thought it better to say no, lest the mother 
should attack. 

This was the same part of Damba coast, as that where 
a mother was seen in the water apparently suckling her 
young, as described ; perhaps it is a favourite nursery. 

One night on Damba I woke up hearing a curious noise 
which, in my sleepy condition, I could not define at first. 
Presently it resolved itself into the grinding of teeth, and 
I realized that a large hippo was grazing on the choice 
grass just by the tent. As I was afraid he might blunder 
into the ropes and bring down the tent, I went out with a 
towel and waved it vigorously, and the huge beast moved 

10 



130 MAMMALS 

off ; it was a dark night, and only a black shape could be 
seen. Hippos are very fond of lush grass which grows 
along low marshy or sandy stretches of shore, and these 
were dubbed " grazing grounds," for the grass was always 
kept short. A magnificent opportunity of photographing 
a grazing hippo was lost because a camera was not to hand. 
In company with the fly boys I was going down to the 
morning's work on the fly beach of Bugalla. As we 
emerged from the bordering strip of forest there was a 
hippo on the sand, grazing quite openly on the grass. 
I walked along the shore towards him to see how close he 
would allow me to come ; he had his back towards me but 
turned round at once, saw me, stared, and went on grazing. 
I continued to approach, thinking it would be good fun 
to pick up a stick and give him an unexpected blow from 
behind. But his guardian angel was true to his duty, 
and when I was within about thirty yards an ibis suddenly 
took to wing with its raucous alarm cry, " Aa-aa-aa." 
The hippo turned round in a fright, made an angry face 
at me, and rushed into the water, leaving me lamenting. 
I should like to conclude my remarks on the hippo by the 
following. A new monthly journal was founded to deal 
with Colonial interests, and a specimen copy of the first 
number reached me on the islands. In it was an account 
of a lecture given by some one on Sleeping Sickness at 
a meeting of a photographic society, wherein were found 
these astonishing statements. The lecturer said it had been 
proved that the Tse-tse could not exist without a feed of 
crocodile's blood (!), and that it was well known that the 
hippo had an inveterate habit of destroying crocodiles' 
eggs (or was he supposed to eat them ? My memory 
fails on this point). Here, then, said the lecturer, is the 
solution of the problem of Sleeping Sickness in a nutshell. 
Preserve the hij)po, and he does the rest ! One can 
picture the establishment of " hippo hatcheries " all 
round the lake, and schools where youngsters will be 



MONKEYS 131 

taught the difference in appearance between the eggs of 
crocodiles and fowls ! 

But perhaps the lecturer was a humorist ? . . . 

Monkeys. 

One species of monkey, a Cercopithecus, lives on the 
islands, but only on the largest : they were found on 
Kome, Damba, Wema and Yempata out of those that 
were visited in the group lying off the north shore of the 
lake, and on Bugalla and the larger isles of the Sesse 
groujD. A very curious fact is their presence on the Isle 
of Nkosi, which is the southernmost of all the Sesse isles, 
quite small and in a very isolated and exposed position ; 
when I visited this islet in 1913 I distinctly heard a 
monkey's voice, though he was not visible (see p. 92). 
The species is of a common type : greenish grey in 
colour, with black face and a white band across the fore- 
head. It has been of very great service in the investigation 
of Sleeping Sickness, since the Trypanosomes which cause 
that disease are also pathogenic to the monkey, which 
can thus be used as a test for infected flies. Hence I had 
one with me on the islands for this purpose, and also 
two others as pets. The " official " one was dubbed 
Tommy, and, of course, had to be kept tied up, as also 
was the older of the two pets, named Wee Man. The 
third, PufRn, was a mere baby, and had not yet become 
sufficiently mischievous for it to be necessary to tie him 
up. When I first had Wee Man he was also allowed to 
run loose, but became so mischievous that when I moved 
to Bugalla he was tied up. 

Being in very constant association with them, one soon 
became thoroughly familiar with their behaviour, their 
moods, facial expressions and language, and soon found 
oneself able to distinguish the meanings of their various 
utterances. 

No less than fourteen sounds are used, although some 



182 MAMMALS 

of them would not be recognized as distinct by any one 
who had not carefully observed the monkeys, for they are 
often of the nature of an alteration in inflection, or accent, 
rather than a different word. 

1. May be called a " General remark,'' and is the com- 
monest expression ; used, seemingly, when a monkey is 
at a loss what to do, or when his attention is attracted 
by something, or when another monkey comes to him, 
etc., etc. 

2. Recognition. — A slight modification of No. 1 was used 
by Wee Man whenever he caught sight of my servant, 
of whom he seemed particularly fond. Often I would 
hear this expression and, looking out, would see the man 
walking about a little way away, and so in time came to 
know what this sound meant, for it was never used on 
any other occasion. It may be expressed by " Wok." 

3. Eagerness. — Another modification of No. 1 indicated 
eagerness ; as, for example, when the monkey saw some 
one bringing a grasshopper which he particularly desired. 

4. Alarm was expressed by still another modification of 
No. 1, and had two forms : 

(a) For a bird of prey overhead, very unmistakable 

and emphatic. 
(6) For a thunderstorm, or a bush fire, which they 

dread very much. 

5. Excitement, as when a monkey sees a boy chasing 
a fowl, or two boys in play chasing one another. This is 
also derived from No. 1. I have heard one of the monkeys 
repeatedly make this noise when he saw a fish eagle chasing 
another away from its private fishing ground. He took 
the greatest interest in the occurrence, watching the eagles 
as they soared around, and being unable to restrain his 
excitement when one swooped down on the other. 

6. Rage. — A quite unmistakable sound, possibly con- 
nected with 5. 




WEE MAN CHOOSING A GRASSHOPPER FROM THE BOX. 
Puffin, behind, has had his. 




WEE MAN (right) AND TOMMY TAKING GRASSHOPPERS. 



To face p. 132^ 



MONKEY LANGUAGE 133 

7. Pai7i. — A kind of squeak. 

8. Cry for help. — A high-pitched squeak. Wee Man used 
to make this as a youngster when he became inextricably 
entangled in his rope. 

9. Melancholy. — A very distinct, long-drawn wail, 
sometimes heard in the forest, presumably indicating that 
the monkey had become separated from the troop. A 
monkey seen in the act of crying thus has a most lugu- 
brious appearance ; the mouth is held in a peculiar 
fashion and one quite expects to see tears rolling down 
the cheeks. 

10. Hunting Call. — One of the most distinct sounds in 
the monkey tongue. When a troop is searching the trees 
for food in the forest an old male sits in a very conspicuous 
tree top and utters a series of barking noises which can be 
most nearly imitated by repeating very rapidly " Kubba- 
kubba-kubba." To this the junior members reply by 
high-pitched squeaks, and the whole troop is thus enabled 
to keep together, as the total amount of noise produced 
is considerable. 

11. Dislike. — A short, expressive word, which may be 
represented by saying beneath one's breath the first two 
letters of the word " come." 

12. Intense dislike and fear. — The last mentioned sound 
is repeated very rapidly and with great energy when a 
monkey sees a snake, or anything that seems to savour of 
a reptile. 

13. A " baby " noise, only made by young monkeys 
when they have been frightened or hurt and run for comfort 
to be cuddled by their mothers or friends. It can be 
represented by the noise " Qurra-qurra-qurra-qurra " 
repeated beneath one's breath. 

Having been for months in close association with the 
pet monkeys, I found their different natures extremely 
interesting, and they were most charming companions, 



184 MAMMALS 

but it was necessary to keep them tied up owing to their 
mischievous dispositions. 

At one time, when very young, Wee Man had been 
allowed to run loose, and whenever I left the house he 
would be unable to resist the temptation of working havoc 
among papers or anything else that took his fancy which 
he could destroy, although he knew quite well he would 
be punished, and showed it by his guilty demeanour when 
I returned. At this time he would frolic around the 
huts of the canoe-men when they were away, and make 
little holes through the grass walls, so that he could, if chased 
when the time came to tie him up for the night, dodge 
in and out of the huts. It was a great game every evening 
to try and find him, and if he managed to hide himself 
away and go to sleep before he was found, it was considered 
that he had won the game ; and he did, quite often ! 
Mischief was a very marked feature of the monkeys' games 
with each other, which were delightful to watch. One 
would be sitting on the bar, a couple of feet above the 
ground, his tail hanging down, and another, with a 
broad grin on his face, would steal up and, seizing the tail 
with both hands, tug furiously in the endeavour to bring 
down the other, who, quite appreciating the joke and also 
grinning, would cling on with all his might. 

They were of a very affectionate disposition, and if 
one was beaten or threatened the other would do its 
utmost to bite the enemy, shrieking with rage the while. 
The baby Puffin, on Bugalla, was not tied up, and 
occasionally got into mischief in the house, when I 
chased him out with threatening gestures. He would 
at once run to the others, who would receive him 
anxiously and carefully examine him to see what damage 
had been sustained, while he made the baby noise to which 
they responded. 

When the three settled down to sleep for the night, 
all cuddled together, they would give each other a long 
kiss, lip to lip ! 




WEE MAN BEING RUDE TO A TORTOISE. 




TOMMY (LEFT) AND WEE MAN IN AN INTERVAL OF A GAME. 

To face p. i3». 



I 



MONKEY AND TORTOISE 135 

But their affection for each other never went to the 
lengths of unselfishness as regards food ; if choice were 
given, a monkey would of course take the largest piece, 
but very often afterwards would drop that and endeavour 
to take from the other the piece which he had himself 
passed over. In fact, their maxim seems to be " the 
other's piece is always better than mine " ! 

Wee Man was the most intelligent of the three, and had 
a more capable-looking head. When his rope became 
very much entangled with that of Tommy, he would look 
at the' tangle for a while and then deliberately try to 
disentangle it by picking up a loop and, as it were, un- 
threading himself by walking through it. Often, if the 
tangle was a simple one, he would succeed, but if the first 
method was not successful he would try walking through 
the loop in a reverse direction. Tommy, however, though 
he might make futile attempts, never succeeded, and seemed 
to do it mechanically because he had seen Wee Man do 
it. This is the only instance I ever saw of the reputed 
imitativeness of a monkey. A certain intelligence was 
also shown in the recognition of zoological afiinity. The 
noise made for a snake has already been described, and 
the same was also made for a fish ; and, one day, having 
found a tortoise, I brought it back to see what Wee Man 
would say to it. 

At first the tortoise withdrew itself within the shell : 
Wee Man came down to look very cautiously at it, 
intensely curious and interested, but when it put its head 
out he hastily retreated to his perch with loud utterance 
of the snake noise. When it began to walk he could not 
restrain his excitement, and danced round and round it, 
chattering, though keeping at a safe distance. I am quite 
sure that this was the first tortoise he had ever met, for 
he had been a captive ever since, as a baby, he was clinging 
to his mother. 

On Bugalla Island, where there was much open grass 



136 MAMMALS 

land as well as clumps of bush and continuous forest, 
when walking in the evening I often came across a troop 
of monkeys among the long grass hunting for grasshoppers, 
which are a great delicacy. A monkey would walk slowly 
and intently through the grass until a grasshopper took 
to flight just in front of him, when with a quick snatch 
he would catch it in his hands. The monkeys always bit 
off the head first, and then the powerful hind legs, if the 
grasshopper kicked much, and the rest was eaten at leisure. 
Even the largest Acrididae, three or four inches long, with 
formidable spines on the hind legs, were eaten with gusto. 
It always made me think of a man eating a live lobster, 
shell, legs and all, and not one only, but half a dozen in 
succession. 

I once saw a small young monkey in a patch of papyrus 
reed, apparently hunting for insects. He climbed up one 
of the tall stems, but just as he reached the top it slowly 
bent over with his weight and he disappeared from view. 
Fortunately for him the papyrus was not growing in 
water. 

In Damba forest I came across a troop, on the 
ground, very busily engaged in turning over dead leaves, 
looking for insects. So pre-occupied were they that I was 
enabled to creep up quite close and watch them before 
one looked up and gave the alarm. 

The captive monkeys were always ready to eat insects, 
and if a species was offered of which they were afra d, 
such as a large bee or powerful ground beetle, they would 
paw it on the ground with rapid strokes of one hand after 
another until it was disabled, when it would be quickly 
picked up and nipped between the teeth, to be subsequently 
eaten at leisure, if desirable. 

One evening on Bugalla I surprised a troop hunting in 
the long grass some little distance away from the nearest 
trees, to which they hastily retreated. A tiny youngster 
who had been put down by his mother was unable to 




i^ 



A BABY MONKEY 137 

escape and took refuge in a small bush, where I easily- 
caught him — a dear little fluffy beast, all head and tail, 
that sat easily on the palm of my hand. Unfortunately 
for him the bush was occupied by a species of very power- 
fully biting ant, and when I got him the poor little monkey 
was being severely bitten by the ants deeply embedded 
in his fur. So I took him on my knee and soothed him 
while I picked out the ants with forceps, the youngster 
sitting quietly as if my attempts at the " cuddling noise " 
were quite intelligible. His parents and friends on the 
neighbouring trees were naturally much alarmed for his 
safety, and danced up and down in impotent rage, with 
shrieks of defiance that could plainly be interpreted as 
** Hurt him if you dare ! " When I had freed him from 
the ants and smoothed him down, I showed him his friends 
on the trees and put him down in the grass ; he ran off 
more or less in the right direction, and I could see him 
thoroughly overhauled by his parents, anxious to see 
what damage had been inflicted, and then conveyed by 
the whole party into the forest. These very young 
monkeys are carried about beneath the belly of the mother, 
their limbs embracing her body, and hands and feet firmly 
grasping the hair on her back. 

The Sitittunga. 

The only antelope on the islands which I visited is the 
Situtunga {Limnotragus or Tragelaphus spekei), known to 
the natives of the islands as " Enjobe." This interesting 
buck was discovered by J. H. Speke in 1862 in the Karagwe 
district, south of the Kagera river. He gives it the native 
name of " Nzoe " and says of it : "It proved to be closely 
allied to a water-boc found by Livingstone on the Ngami 
Lake, but instead of being striped was very faintly 
spotted, and so long were its toes it could hardly walk on 
the dry ground ; whilst its coat, also well adapted to the 
moist element it lived in, was long, and of such excellent 



188 MAMMALS 

quality that the natives prize it for wearing almost more 
then any other of the antelope tribe. The only food it 
would eat were the tops of the tall papyrus rushes ; but 
though it ate and drank freely, and lay down very 
quietly, it always charged with ferocity any person who 
went near it." 

The Enjobe is about the size of a donkey. The male has 
beautiful horns, long and spirally twisted, with almost 
translucent tips ; the females are hornless. The colour 
varies considerably ; the young males are bright foxy 
red, marked with white, adult males are darker brown, 
but I have seen an adult female of the same colour, 
although typically they are more brightly coloured like 
the young male. 

This antelope with its elongate hooves is well known to 
haunt swamps for which its deeply cleft feet are suitable, 
in the same manner as are those of the reindeer for snow 
or of the camel for sand. 

It is mentioned in books as spending its days immersed 
in water among papyrus, etc., and is apparently considered 
as an animal confined to swamps. On the islands, however, 
it is a creature of different habits, possibly owing to the 
entire absence of enemies, human or otherwise, from which 
on the mainland it takes refuge in swamps. Indeed, it now 
behaves much like its close ally the bushbuck, called 
" Engabi " by the natives. On some of the islands which 
it inhabits there are no papyrus swamps, and during the 
day time I often disturbed Enjobe from their resting 
places in the forest belt near the water. 

In the evening they could be seen coming out on to the 
open grass covered spaces and browsing on bushes, 
especially " Oluzibaziba," the Euphorbiaceous Alchornea 
chordata, of which they eat the young tips. 

The bushbuck may well have had similar habits on the 
larger islands in former days until it was exterminated. 
The Situtunga, on the other hand, could have taken refuge 



SITUTUNGA 189 

in the water, as it now docs on the mainland. Since the 
removal of the islanders, however, which was completed 
in 1909, its habits have become changed, and it is multi- 
plying very quickly in the absence of all enemies. 

Major R. Meinertzhagen, F.Z.S., visited Bugalla from a 
steamer during the war in October 1915, and examined 
several Situtunga, finding interesting differences from the 
mainland type ; the horns diverged more widely. But 
the specimens from the much smaller and more isolated 
islet of Nkosi showed further deviation to such an extent 
that they are given sub-specific rank.^ 

The feet show a slight return from the specialized 
narrow hoof of the type, for in the Nkosi animals the 
hooves are proportionately broader, and in a young animal 
were " no longer than one would expect to find in a young 
bushbuck of his age." 

The horns also are more like those of a bushbuck, and 
the colour of the adult male was noted as " of a uniform 
dull mouse colour and not a dark brown " ; the animals 
are also larger than the typical mainland forms. 

It is remarkably interesting that this change in structure 
can be noted together with the change of habits ; the 
Nkosi animals are losing the high specialization, correlated 
with the peculiar mode of life among swamps, which 
characterizes the Situtunga discovered by Speke. 

The Situtunga could frequently be heard barking at 
night, the call being somewhat like that of the bushbuck 
but distinct from it, rather more muffled and less dog- 
like. 

The following may be cited as evidence of the effect of 
the removal of all inhabitants from the islands. 

Nsadzi, the long narrow isle lying due south of Entebbe, 
was free from this antelope when inhabited, according to 
native testimony, although the densely forested eastern 
end provides ample shelter. When I visited it in 1914 with 

^ Proceedings of the Zoological Society, June, 1916, pp. 375-81. 



140 MAMMALS 

Fiske he found footprints, and later on I found abundant 
evidence that Situtunga at least visit Nsadzi. I have 
also found bushes browsed by them on Ngamba, between 
Nsadzi and Kome, on which latter large island they abound, 
so that it is probable they had crossed to Nsadzi from 
Kome, using Ngamba as a stepping stone, for it is well 
known that they swim readily. The importance of these 
movements from the point of view of Sleeping Sick- 
ness has already been discussed in Chapter II, pp. 
28-29. 

The smallest island on which I have seen Enjobe is the 
previously mentioned Nkosi, lying to the extreme south 
of the Sesse archipelago, and very exposed. Several were 
seen there on a visit (see p. 91), and areas of grass 
were kept close cropped by their grazing. It seems 
almost certain that they must swim to and from this 
tiny island from the larger isles to the north. 



Otters. 

Otters abound in the lake, as might be expected, and 
one is glad to feel that their numbers are steadily 
increasing now that they can no longer be destroyed for 
their skins by the islanders. There can be few animals 
more beautiful than otters in the water ; they are so 
lithe and graceful and sleek, and so full of the joie cle 
vivre. I remember well one very hot day when I was 
visiting the little islet Kizima. Looking down from the 
top of a little cliff into the water I saw below some half 
dozen otters sporting in the water and tying themselves 
into knots, but in a very leisurely way, as if it was too hot 
for much exertion. On another occasion off Tavu Isle 
there were about a dozen, fishing and playing with their 
catches in a very delightful sportive mood ; throwing 
the fish up into the air and catching it again. One lay 
on his back in the water in a most ludicrous attitude, 



OTTERS— LEOPARD 141 

with a fish in his mouth and hind feet and tail sticking 
up out of the water. 

The size of fish that otters can tackle is very surprising. 
On Ziro Isle, in 1919, I saw the remains of a very large 
Silurid fish, which had evidently been dragged up on to a 
rock high above water by one or more otters which had 
eaten all except the shoulders and the large flat bony head, 
measuring 12 by 9 inches. This part that remained was 
taken to camp, and was found to weigh twenty pounds ! 
So the fish, which the natives called " Akasonzi," would 
probably have weighed forty pounds at least. It was 
the largest one the natives had ever seen. 

The otters in Kingsley's Water Babies are described as 
making a queer chorus of squealing noises, but I never 
heard a sound that could be ascribed to an otter, even 
at night, save when one comes up to breathe close by, 
and emits a short grunt before diving again. 

Leopard. 

The larger carnivora were not met with on the islands 
save for one exception. On Kibibi, in January 1919, fresh 
spoor of a leopard was seen on the wet sand on two succes- 
sive visits nearly a week apart. The leopard must have 
swum from the coast of the mainland across at least 2| miles 
of open water. (See map.) The spoor was seen very fresh 
on both January 17th and 22nd, there having been heavy 
rain between the two visits. So it would seem that the 
animal was there all the time, although there cannot have 
been much food for it. On Kibibi there are neither buck 
nor monkej^s, and there are no game birds (save an 
occasional bustard, quail, or forest francolin) on any island 
that I have visited. Presumably the leopard managed to 
catch fish or ate crabs that it found on the beach ! 

Mongoose. 
Animals of the civet cat tribe ( Viverridae) were not often 



142 MAMMALS 

met with on the islands, and then only on the very largest. 
A pair of genets was once seen on Kome, their long snaky 
bodies, with spotted coats, and short legs being quite 
unmistakable, even though they were only seen darting 
away in alarm. 

On Damba one day in 1911,1 had a delightful experience. 
I was sitting quietly by a clump of bushes, watching for 
bee-eaters at the edge of the forest, some 30 yards away, 
and keeping as motionless as possible. A beautiful 
mongoose, of a rich red-brownish green colour, with tail 
all fluffed out, walked across a little grassy bay in the edge 
of the forest, very full of vigour, but not in a hurry, and 
disappeared again among the bushes. Shortly afterwards 
there was heard an agitated quacking and cackling from 
the jungle on my left, and an Egyptian goose came across 
the grass in front of me, and only a few yards away, 
followed by the mongoose. 

The goose fluttered along making a great fuss, apparently 
just keeping out of reach of the pursuer. It seemed to 
me, however, that the mongoose was not exerting himself 
very much, as if he thought that the obviously disabled 
bird in front must very soon fall an easy prey. The two 
passed into the jungle on my right, and the deluded 
mongoose lost his prey. Shortly afterwards I saw him 
again, walking across the little bay, but the ruse had 
been successful ; the goose had drawn him away from a 
brood of babies, and while he had been chasing one parent 
the other had led the goslings away in another direction, 
and I could see them swimming away to a marshy bit of 
land where they were safe for the time. But a few days 
later I saw that the number of goslings was much 
diminished, so the mongoose may have been more success- 
ful a second time, knowing the trick that had been played 
on him. 

It was very interesting to see this old, old trick actually 
succeed. 




A FAVOURITE HAUNT OF SITUTUNGA ON BUGALLA. 

They feed in the evening on the bushes at the edge of the forest belt which slopes steeply to 

the water. 

By permission of the Royal Society and the Controller, H.M. Stationery Office. 




A BAT CAUGHT ON TENT AT JINJA. 



To (ace p. 142, 



BATS 143 



Bats. 



Bats abound among the dense vegetation of the old 
banana plantations, and may often be seen in the day 
time hanging from the midrib of a banana leaf. The 
caves found on Kimmi, Damba and other isles shelter 
numbers of the smaller species, named " Akawundo " by 
the natives. I shot a few of these one morning in order 
to investigate the contents of their stomachs, but although 
it was only about 9 o'clock, their stomachs were quite 
empty. The noise reverberating in the cave was so 
distasteful to the bats that for a long while they did not 
return ; possibly their instinct warned them that such 
a noise could only, in the experience of the race, have 
been caused by rock falls making the cave unsafe. 

I had a curious experience at Jinja one evening in 1910. 
Hearing an animal scrambling about over the roof of the 
tent and being unable to drive it away by repeatedly 
striking the canvas, I went out with a lantern and found to 
my surprise that it was not a mouse but a bat, whose 
photograph is reproduced (p. 142). It was a more active 
walker than others that I have encountered, and seemed 
quite unwilling to fly. It had possibly been crawling 
about on the roof after insects that were attracted to the 
light. 

The much larger frugivorous bats, commonly called 
" Flying Foxes," and by the natives " Ekinyira," 
occasionally gathered together in great numbers, possibly 
for breeding purposes. This was first noticed on Bunyama 
in January 1912, and, later, on Ngamba in March and 
April 1914. 

They assemble among dense creepers, and may be heard 
chattering, and also smelt, before a landing is made. 

When disturbed they made a prodigious noise, scrambling 
about and squeaking loudly before taking to flight and 
circling round looking for a new resting place. 



144 MAMMALS 

Although I visited Ngamba every week between March 
and August 1914, I did not find these bats congregated 
after April. 

Since the expanse of wings is about two feet, they look 
large creatures in flight, and the beating of the wings 
makes a considerable noise when one disturbs a large 
congregation. 

At night the " Ekinyira " in the forest keeps up a most 
insistent loud noise at intervals of about a second. For a 
long while I thought it was produced by a large frog. 
It is a sharp note, between a high-pitched croak and a 
grunt, with something of a bark in it. It may be heard 
from shortly after sunset for hours on end, and, if one 
awakes in the middle of the night, may still be heard 
coming from the same spot ! 



CHAPTER VIII 

BIRDS 

Ornithology is a subject to which I have devoted less 
time and observation than entomology, so that I have not 
so much to say about birds because of my ignorance of 
their identity. 

In writing this chapter I have been much indebted to 
Mr. C. F. Belcher, of Uganda, who has kindly given me 
the scientific names of such species as are dealt with, 
and also some of the native names which I had not found 
out. 

The arrangement and nomenclature is according to 
Reichenow. 

Perhaps the most striking ornithological feature of the 
islands is the difference of their fauna from that of the 
adjoining coast of the mainland. 

I am, of course, only speaking of the islands that I 
know weU, those lying parallel to the north coast of the 
lake between Entebbe and Jinja, and Bugalla in the 
north-west corner of the lake. The differences that have 
been noted will be mentioned as the various groups are 
alluded to. 

Gulls are some of the first birds noticed by the traveller 
on the lake, and while I was on Damba Island in 1911 
I saw a good deal of them. Some low rocks in the water 
lay off the point on which I was camped, and for some 
reason these were a favourite resort of gulls and many 
other birds, so that there was a bigger collection there 
than at any other place I know among the islands. 

11 i« 



146 BIRDS 

At least two species of gull (Larus fusciis and cirrho- 
cephalus), one, larger, with black back, the other grey, 
were always chattering and screaming there, together 
with terns, cormorants, darters, pratincoles, sandpipers, 
goliath herons and other herons, amongst them a 
magnificent snow white species seldom seen, but there in 
some numbers (? Herodias alba), white egrets and the 
white egret-like buff backed heron, the open-bill and 
another stork, Egyptian geese, and sometimes ibises, 
either the black and white sacred species or the dark 
greenish black Hagedash ibis. 

The gulls are much more noisy before stormy weather, 
and were quite useful as weather prophets. It seemed 
to me, also, that one did not see much of the terns 
except in windy weather, when they were noticeable flying 
about close to the land. Gulls are known to the natives 
as " Enkobyo-kobyo," and terns (Hydrochelidon leucoptera) 
by a name that sounded like " Akalerwe," but I would 
not be certain of its correctness. Two species were noted. 
It often seemed curious to me that I never met with the 
nests of gulls on the coasts of the islands ; possibly they 
do not breed close to the water. 

They feed on dead fish and other flotsam on the surface 
of the lake, but one has been seen in close attention on a 
number of cormorants that were fishing in shallow water. 
When one came up to the surface with a wriggling fish 
in its mouth the gull swooped down upon it, and in self 
defence the cormorant had to dive again with the fish 
uns wallowed. This happened repeatedly until the passing 
of the canoe disturbed the birds, so that I could not see 
whether the gull had made the cormorant give up its 
prize. 

Cormorants naturally abound among the islands, and 
soon become familiar sights. One is much puzzled by the 
variety of markings of the larger birds {Phalacrocorax 
lucidus). They may be black without any white, or with 



CORMORANTS 147 

snow white throat and breast, with or without a round 
white patch on the side just behind the angle of the 
wing. 

A smaller species (Phalacrocorax africanus) is all black, 
and nearly always very ragged looking ; indeed, one cannot 
feel any affection for the cormorants, they are smelly 
and unattractive. Natives call the smallest specimens 
" Semirindi," the larger ones, without much white, 
" Ensogwe," and the largest white breasted specimens are 
named " Engadala," but most natives class them all, 
together with the darters, as " Ensogwe." 

These birds have their regular " rookeries " where they 
breed year after year, so that the ambatch trees on which 
they continually perch and build their loose nests of 
sticks become flattened down and often look very unhappy. 
The birds when sitting on the nests have a curious habit 
of rapidly moving in and out the loose skin of the " chin," 
in somewhat the same way as a fowl when gasping for 
breath in very hot weather. It is possibly due to the 
same cause in both cases, as the cormorants sit on the 
nests exposed to the full blaze of the sun. 

I first noticed this when watching the nesting birds on 
the islands of the Nile at Jinja, below the falls. Cor- 
morants abound here, and swim fearlessly about amidst 
the turbulent eddies immediately below the actual cataract, 
where one would think they must be beaten against the 
rocks. 

About sunset large numbers of these birds return from 
the lake, flying up the narrow gulf until they reach the 
falls where the gulf becomes the river. Here, in 1910, 
I often noticed a very curious trick of flight. 

When the leading bird of the flock arrived over the 
falls it would suddenly close the right wing so that it 
fell down sideways for some twenty feet or so, to recover 
with perfect ease and resume its former steady flight. 
Often several would do this in succession, as if playing 



148 BIRDS 

follow-my-leader, but I have never seen this trick played 
anywhere else. 

Occasionally a single bird winging its way home utters 
a rhythmic croak at intervals, strongly suggesting a man 
loudly panting for breath. They are not exactly songsters ; 
their noises are more of the nature of quackings than 
anything else. Except for the trick above mentioned one 
does not see much sign of the joie de vivre in cormorants ; 
they seem to find life a serious business, and have to work 
hard for a living. When resting, and possibly digesting, 
on the branches of their favourite trees, they often spread 
their wings out on each side of the body, as if they felt 
the heat, or were holding them out to dry, although so 
oily are their feathers that they cannot really get wet. 
It always amused the canoe-men, when we were going 
along, to see one of these birds suddenly appear on the 
surface, often with a wriggling fish in its beak, hastily 
look round, and either dive again or take to flight. Being 
heavy birds, they have to paddle their feet along the 
surface for some distance before their wings have developed 
enough momentum to lift them up. 

Closely allied to the cormorants, and grouped with 
them by the natives under the name " Ensogwe," are the 
snaky-necked Darters (Anhinga rufa), often erroneously 
called Divers, which name belongs properly to the 
marine Colymbi. 

These are not nearly so abundant as the cormorants, 
from which they are easily distinguished by the much 
smaller head and very long slender neck, bent upon itself 
with a curious kink. Like the cormorants, these birds 
take life very seriously, and are equally unattractive, 
though their quaintness is interesting. They are certainly 
most efficient water birds and fly well, but are ungraceful 
and malodorous — at any rate in quantity. They are, 
however, of somewhat less dingy plumage, and in the 
breeding season become almost brightly coloured with 
yellowish and brown tints. 



GEESE 149 

Pelicans have only been seen in the narrow channel 
between Bugalla Island and Bukakata port on the Buddu 
coast of the west of the lake. 

They may also be seen in Kavirondo gulf, which is very 
shallow and muddy, but why they do not occur elsewhere 
on the sheltered waters among the islands it is difficult 
to explain. 

Geese are, of course, numerous on Lake Victoria, but 
I confess not so numerous as I expected to find them, 
and ducks were very rarely seen. I never saw on Lake 
Victoria anything approaching the hosts of brown ducks 
seen in 1916 on Lake Bunyonyi in the Kigezi district of 
the south-west corner of Uganda, or in 1918 on Singidda 
Lake at the southern end of the East African rift valley, 
or on the marshy land along the central railway of ex- 
German East Africa, near Dodoma, in 1917. The native 
name " Embata " applies to both geese and ducks. The 
Egyptian, or Zambesi {Chenalopex oegyptiacus) goose, well 
known over so large a part of Africa, and on ornamental 
waters at home, is the species most often met with, and is 
usually found in little companies of two or three, or some- 
times half a dozen. It prefers especially an open shore of 
flat rock or sandy beach — the white sand of Nsadzi beach 
was a very favoured spot, and one could always reckon on 
finding at least a pair there. 

They are handsome birds with their mottled brown and 
grey plumage, and green and white speculum on the wings, 
and walk easily, carrying themselves well without waddling. 
As one moves along the beach towards them their agitation 
shows itself by loud cacklings, until they finally take to 
flight and make a half circle over the water, returning to 
shore a little further away. A wounded one that had 
been shot and was pursued by a canoe endeavoured to 
save itself by diving, but I think this bird only does so 
in its utmost extremity. 

A nest was found, on July 25, 1914, at the foot of a tree 



150 BIRDS 

behind a bank of bushes and reeds on Kimmi Island ; 
excavated in a bed of dead diy leaves and beautifully 
lined with warm down, it contained four white eggs. 
About a week later, however, I found only two eggs in 
the nest, so that possibly some had been devoured by 
Varanus or a snake. 

I have related elsewhere how a mongoose that ardently 
desired a gosling was frustrated by an old, old trick 
played upon it by one of the parents. 

The large black and white spur-winged goose (Plectrop- 
terus gambensis) is not so plentiful as the Egyptian goose, 
but is a much better bird for the table. I saw it so seldom 
that I have no notes about it. 

Similarly with the brightly coloured dainty little pigmy 
goose {Nettopus auritus), which is found sparsely along 
rush fringed stretches of shore, such as the north coast 
of Bugalla and the channel between Damba and Kome. 

Rather curious little birds are Pratincoles {Galacto- 
chrysea emini), which may be seen sitting on small rock 
islets. They seem very sluggish birds, and are not very 
interesting or attractive. Short legged, with rather slender 
bodies of grey colour, the rounded heads bearing a short 
beak, the pratincole is called " Akasalu " by the natives. 

Of the Plovers and their allies the most noticeable species 
on the islands is a stone curlew {Oedicnemus vermiculatus), 
known to the natives as " Mutunwa." Almost every 
beach of gravel or sand or flat rocky shore has a pair or 
more of these birds, which lay their eggs there, placing 
the two in a slight hollow, without any attempt at a nest. 

If one interferes with eggs or young they are apparently 
removed by the parents. I first noticed this on Damba 
beach, where I found a pair of eggs lying on the shingle 
and examined them ; but next day they had disappeared. 
Again, on Ngamba, I came across a young bird, with the 
other just beginning to make its way through the shell. 
I helped it out, a poor little bedraggled feebly chirping 




NEST OF EGYPTIAN GOOSE UNDER TREE. 



1 


^^^^^^^^^^^^^^^^i,^%- .^ *^-»^i "^^^^^^^^^^^H 




■1 




' ^> 


^ 







NEST OF STON'E CURLEW {OEDICNEMUS). 
Two £ggs lie in front of the stick lying obliquely across the left centre of the picture. 



To face p. 150, 



STONE CURLEW 



151 



object, and left it there ; but a few days later both had 
disappeared. It is, of course, possible that they had 
really been eaten by a Varanus lizard ; I have elsewhere 
described how one seized a bird I had shot. The Mutunwa 
has a most curious habit of, as it were, shrugging its 
shoulders, a habit shared by many of the kingfishers, of 
which the meaning is quite obscure. They are certainly 
decidedly procryptic birds, and this unnecessary move- 
ment helps to reveal them when they might otherwise 
escape notice. 

Their characteristic cry is often heard at night, especially 
in bright moonlight. It begins with a single high- 
pitched note, sharply accentuated, and then a series 
beginning lower than the first, rising to the same level 
and falling again — a very mournful cadence. It may be 
represented graphically thus : 



d! 



>l j 



llllfe, 



One stone curlew that I shot on Nsadzi in order to in- 
vestigate its stomach contents had eaten a cricket and 
apparently a small frog, so far as I could tell from the 
slender bones that were aU that was left. 

The common Sandpiper [Tringoides hypoleucos) is 
abundant on beaches or flat rocks, very often singly, 
sometimes in small flocks. 

It may be seen at the Ripon falls paddling about in 
the water at the very edge of the cascade, occasionally 
having to leap away from an unusually large patter of 
spray or a rush of water. Possibly it feeds upon the 
Simulium larvae which adhere to the rocks in abundance 
in such localities. 



152 BIRDS 

I once saw on Damba some extraordinarily long legged 
birds that presumably were Stilts, but they are far from 
common. The locality was a very marshy piece of shore, 
also frequented by snipe. 

On Kome, in 1914, were seen some plovers which had 
not been met with previously, nor have I seen them since, 
although there are large areas of marshy shore similar to 
the locality where they were seen. 

The colouration was roughly as follows : Back grey, 
belly white, chest and back of neck black, face and front 
of neck white. When flying the bird shows black and white 
wings. Subsequently, in ex-German East Africa, a bird 
of something the same type was seen commonly on open 
grassy plains. This was termed " Kibiki " by South 
Africans. 

Another species of the plover group was heard flying 
overhead at night time on Kome. Its cry became very 
familiar, and was apparently responsible for the name 
" Empunya " given to the bird by the natives. Since 
the meaning of this word would be something connected 
with the word for " to smell, or emit an odour," it is 
probably merely onomatopoeic, and is quite descriptive of 
the cry. 

Cra7ies are represented in Uganda by one species of 
crowned crane (Balearica regulorum), a most orna- 
mental and graceful bird which would be a splendid 
addition to the peacocks and pheasants often kept to 
ornament a park. The soft brown and grey and yellow 
hues, with velvety black head furnished with scarlet 
wattles and erectile crest, make it a most lovely bird, 
and its quaint antics when with others of its kind give it 
additional interest. 

Unfortunately they are very seldom met with on the 
smaller islands, and even on Kome and Bugalla are rare ; 
and I never saw a flock such as may be seen at Entebbe 
or Jinja. Their cry has earned for them the Luganda 



BUSTARDS— IJLY TROTTER— IBIS 153 

name "E'ngali." The booming noise which they make at 
night, before rain, has been already alluded to, and the 
curious ignorance of the natives, who assign the noise to 
the puff adder ! 

Next come the Bustards, of which a single species 
{Otis melanog aster) known as " Olunyonkante " occurs on 
islands where there is a sufficiently large open grassy 
area. This species shows black and white wings when 
flying, and has a most ridiculous little call note. One hears 
first a very short low whistle, followed after a few seconds 
by a single sharp but very quiet note like a bubble 
bursting. The peculiar native name would seem to indicate 
that the native considers it to suck cows, so that this bird 
holds a place in folklore analogous to our " goat sucker " 
in England. 

Birds of the Rail family were plentiful among the reeds 
and rushes of the lake shore. One, looking much like 
our English moorhen, was responsible for making a most 
extraordinary noise among thick cover — a sort of grunting, 
squealing and whining, quite indescribable and very 
unlike a bird noise. The pretty brown, yellow and black 
Lily trotter may conveniently be placed here, " Akatassa " 
{Actophilus africanus). It is seen where there are enough 
water lily leaves or thick vegetation in the water for it 
to run over, its very long toes supporting it by distributing 
its weight over a large area. It is a very quiet bird, and 
one rarely heard it make any kind of noise unless it was 
angrily scolding at and driving away a trespasser on its 
private hunting ground. 

We next come to the Ibises, of which I only know two 
species on the islands, the most conspicuous being the 
dark greenish black Hagedash ibis, known to the natives 
as " Empavana," the word being an attempt to reproduce 
its very characteristic cry, which can be indicated by 
" Aa-aa-aa," This is a very annoying bird if one is 
anxious to approach an animal without being noticed, 



154, BIRDS 

for it is very nervous and quickly takes to flight with noisy 
beating of wings and raucous lamenting cry, frightening 
everything within earshot, so that it must be a great 
nuisance to sportsmen. I have already related how one 
of them frustrated my hoped for interview with a hippo. 
Sometimes these birds perch on a tree top, at other times 
sit among the rushes and bushes on the shore, but wher- 
ever they are their wailing cry betrays them. When 
flushed they make a great noise with the hurried strokes 
of their wings and have a characteristic flight, interposing 
an extra quick beat here and there until they feel steady 
in the air. Presumably the main object is to rise quickly 
from the ground, and not to place a great horizontal 
distance between themselves and the disturber of the 
peace. 

The other species is the handsome sacred ibis (Ibis 
oethio])ica), whose plumage, half black, half white, makes 
it easy to recognize. It is very far from common, and is 
only to be seen occasionally here and there, so that it is 
unfamiliar to the natives, and I could obtain no native 
name for it. During 1914 there was usually to be seen 
one on a rock off Kizima Islet, and it was noted to be a 
very silent bird, thus contrasting strangely with its 
relative. I did not notice the hurried flight, with inter- 
posed beat, so characteristic of the Hagedash ibis. 

Of Storks, several species are noticeable, particularly the 
curious " open-billed " species {Anastomus lamelligerus), 
the two halves of whose beak do not meet along the middle 
of the bill, giving the bird an unusual appearance. It is 
rather an uncouth and ungraceful black bird, met with 
along the shore, where it is said to feed on the large 
Ampullaria " water snails," its curious bill being adapted 
to enable it to deal with their strong shells. The natives 
call it " Enkonamasonko," which shows that they know 
its habits, " E'sonko " (jilural Masonko) meaning " shell," 
and " Oku-kona " meaning " To knock." 



STORKS 155 

It is quite a common bird, but only at certain places, 
usually an open rocky shore where the Ampullariae are 
easily found. 

Another all black stork of about the same size {Ciconia 
nigra) is often mistaken by the natives for the " Mpavana," 
so that at first when one asked its name one always got 
the name for the ibis. However, a more observant 
native distinguished it as " Sombabyuma," a curious 
name which implies that this bird collects pieces of 
iron ! 

Another stork of about the same size, but black and 
white {Abdimia abdimii), appears from time to time in 
large flocks that, after soaring round and round high up 
in the air, descend to open grass land and eat grasshoppers. 

The natives call it by the name " Enunda," which is 
apparently their equivalent for the English " stork," 
for they applied the same name to a specimen of the fine 
saddle-billed stork {Ephippiorhynchus senegalensis), which 
I once, and only once, saw on the shore of Buvu, in 
the Sesse Archipelago, in 1912. It is a fine bird, with 
blue-black and glossy bottle-green and white plumage, 
the huge bill being crimson and black with a " saddle " 
of yellow. The European stork, curiously enough, was 
never met with on the islands, and I had never seen it 
until I found it numerous in the Singidda district of ex- 
German East Africa, at the southern end of the great 
East African Rift valley — this was in February 1918. 
The remarkable Nilotic whale headed stork {Balceniceps 
rex) was also absent from the islands, perhaps because 
there was not a large enough area of papyrus swamp. 

The Hammer-head, or Tufted Umbre {Scopus umbretta), 
is not uncommon along the shore, although one never 
sees more than one at a time, for it appears to be a solitary 
bird. It is of a dull dark brown and has a large head, 
tufted as its name implies, with a heavy bill. It is found 
standing in the shallow water of a sheltered pool or bay, 



156 BIRDS 

apparently watching for fish as do the herons, but possibly 
also dozing, for I think it is more crepuscular or nocturnal 
than diurnal. 

Flamingoes, somewhat to my surprise, were never met 
with on the Victoria Nyanja, but I cannot say why. 
The lake abounds in shallow bays and quiet sheltered 
waters, where one would think flamingoes would find all 
they desire. 

Herons and their aUies are numerous on the islands, 
as might be expected. The finest bird to be seen on the 
lake shore is the goliath heron, which, like many other 
species of the Uganda fauna, extends its distribution to 
the west coast. 

This magnificent bird is known to the natives as 
" Kimbala," ^ and may be seen standing at the edge of the 
water or on rocks on every island. I should think 
there may be one to every two miles of coast line. Such 
large birds would, of course, require extensive fishing 
grounds, and I have twice seen disputes between a goliath 
heron and a fish eagle. 

On the first occasion I was examining the coast of 
Buvumira Isle, in 1912, when one of these great birds was 
seen flying over the surface of the water with a fish eagle 
in hot pursuit. When the eagle came uncomfortably near 
the heron dropped on to the surface of the water and sat 
there with his beak in a defensive position ready to jab 
at the eagle should it be unwise enough to attack, and 
turning round as so to keejD facing the eagle from whatever 
direction it threatened, erecting a crest of feathers on top 
of its head when the eagle came near. The eagle did 
not venture to attack, and drew off a little, whereupon 
the heron took to flight again, its enormous wings beating 
the air with slow strokes. Seeing its enemy again on the 
wing the eagle made another dash at it, whereupon the 

^ Some less observant natives call this bird " Balwa," but I think this 
name belongs to another heron, possibly the Ardea purpurea. 



GOLIATH HERON AND EAGLE 157 

heron repeated its defensive tactics, dropped on to the 
water, and took up the same attitude as before. 

As soon as the eagle drew off the heron took to wing 
again and this time was not pursued ; the eagle, being 
satisfied that the trespasser had been driven from the private 
fishing grounds, returned victorious to its favourite perch, 
while the heron slowly disappeared into the distance. 

On the second occasion when the two birds were seen 
in conflict, the heron had the best of it. This was in 
1913, when I was going down to see Nkosi Islet, the 
southernmost of all the Sesse group. While passing down 
the channel between Kirugu and Buguye, I saw, on the 
islet Lula, a fish eagle swoop down upon a goliath heron 
that was standing on the shore, but presumably trespassing 
on the eagle's preserves. 

There was some rough and tumble business, and then the 
eagle was seen on the ground, and whenever it moved the 
heron jabbed viciously at it with its formidable beak, 
and, I think, had one foot on the eagle to hold it down. 
A considerable noise was made, but I think the heron was 
chiefly responsible for the very savage snarling and grunting 
sounds that came from the pair. I confess my sympathies 
were with the eagle, who seemed to be getting much the 
worst of it, but eventually managed to disengage and 
fly away, and the heron did not pursue. 

It would seem as if the eagle was superior on the wing, 
and the heron knew it, but was in the stronger position 
on the ground. In the case first described the heron 
was at first seen on the ground, but took to wing at the 
approach of the canoe, when the eagle gave chase ; presum- 
ably it had not dared to attack before. The hoarse, 
raucous cry of the Kimbala is quite startling when one 
suddenly gets up, frightened by a gunshot, from a thick 
bed of rushes where it had been standing unperceived. 
It is a handsome bird, coloured with various shades of 
brown and purplish grey. It is curious that I have never 



158 BIRDS 

seen one actually feeding, but presumably it catches fish 
and frogs like other herons. 

Several other species are to be seen. A grey one is 
known as " Sekanyolya " {Ardea melanocephala), but I 
have nothing to say about them. 

An extremely beautiful but seldom seen species was 
noted in 1918 on rocks off Damba Island, a locality that 
has been alluded to before. There were seen, among many 
other birds, half a dozen great white herons (Herodias 
alba), collected on one small low rock, their pure white 
plumage and graceful build arousing intense admiration. 
Subsequently, some were seen on other islands, but they 
are by no means abundant, and the natives have no 
name for them other than " Enyange nene," i.e. large 
egrets. 

But the Egret {Egretta garzetta) is more slender, smaller, 
and has a black bill and legs. It is quite common on the 
islands, and may constantly be seen paddling at the edge 
of the water on the beach or on flat rocks where the waves 
are breaking, picking up small fish from the water, or 
investigating small pools for frogs, its pure white plumage 
making it very conspicuous. 

Although they usually fish by themselves, egrets may 
often be seen at sunset in small flocks wending their way 
home, flying slowly over the surface of the blue water 
with hoarse croaks. 

They nest in much the same situations as are chosen 
by darters and cormorants, namely, ambatch trees growing 
in shallow water. In January 1919 I found some young 
almost ready to leave the nests. 

A bird that is often mistaken for the true egret is 
the white buff-backed heron [Bubulcus ibis), which is 
extremely abundant at Jinja or Entebbe, where flocks 
may be seen in attendance on cattle, ready to pounce on 
the grasshoppers and other prey disturbed by the move- 
ments of the grazing beasts. But they are not so slenderly 



PIGEONS- FR ANCOLINS 159 

built as the more graceful egret, and their shorter, stouter 
bills are yellow instead of black, as also are their legs. 

Curiously enough they are, on the islands, no more 
plentiful than the true egret, perhaps because there are 
no cattle to collect them together in flocks. 

Doves were common, but several notable species found 
on the mainland were never seen on the islands — for 
example, the small, long tailed ^na capensis, seen at Jinja. 
A forest species, whose long drawn out call was heard 
coming from the tops of tall trees when I examined patches 
of forest on the Kyagwe coast, was never heard in the 
island forests. The beautiful green fruit pigeon (Viiiago), 
with red bill, was quite common, as might be expected 
from the abundance of fig trees growing on the rocky 
shores. It has a long and rather complicated call, which 
one soon got to know, but found impossible to imitate. 

Game Birds are chiefly remarkable for their absence. 
No guinea fowls were ever seen or heard, nor any of the 
larger " bush-partridge " (species of Francolin), It is 
possible that they had been exterminated by natives 
trapping them in the old days before the outbreak of 
Sleeping Sickness. 

A certain loud, ringing cry was so frequently heard 
from the depths of the forest belt on Bugalla that I soon 
became thoroughly familiar with it. But it was long 
before I found out what was the bird responsible for it. 
One day in the forest a bird that at the time was noted 
to be of the partridge type, ran out from a clump of thick 
undergrowth, but seeing me almost at once dived back 
again. It was undoubtedly the bird that was responsible 
for the well-known cry that had been coming from that 
spot. Further knowledge of birds made it obvious that 
this must have been one of the forest Francolins. 

I believe that this bird has much increased its range 
on the islands since those days. Between December 3rd, 
1918, and mid-February 1919, I examined thoroughly a 



160 BIRDS 

chain of islands which I had visited in 1914 with Mr. 
Fiske. On the second tour this forest Francolin was 
heard calling on every isle that had forest to shelter it, 
where it was not noticed in 1914. 

The only other game birds of the islands are Quails, 
of which two species were met with ; but save that one is 
much larger than the other there is nothing to be said 
about them. 

Birds of Prey. — The most conspicuous bird of prey is, 
of course, the glorious white breasted Fish Eagle or 
" Empungu " {Haliaetus vocifer), which is literally quite a 
feature of the landscape. Its pure white head, neck and 
breast, set off by rich red brown and black on body and 
wings, render it visible afar when perched on a tree 
top or prominent branch hanging over the water. Its 
joyous scream, uttered when soaring round and round 
high in the air, or when perched on the tree, is a most 
delightful noise, full of life and vigour. When screaming 
the bird throws back its head until it almost touches the 
back, and the loud cry is responded to by its mate, for 
they seem to live together in couples. 

The noise made by the rush of air between the pinions 
when one of these superb birds sees a fish at the surface 
and stoops to secure it can be heard before one has actually 
seen the bird, and amounts to a loud roar. Sometimes 
the bird chooses a fish of such size that it cannot lift it. 
An officer of the Uganda Marine told me that he had seen 
one taken under water by a fish in which its talons were 
presumably inextricably fixed. It was probably one of 
the large lung fishes which had come to the surface for 
a breath of air. 

So far as I can remember, however, the eagle does not 
usually plunge quite into the water, but checks itself 
before the impact, neatly picking up the wriggling prey 
with its feet, and carrying it off to a favourite perch. 

During brilliantly fine weather, when there is usually 




NEST OF OSPREY ( " MAKWANZl ") 



To face p. i6o 



FISH EAGLES 161 

a steady southerly or south-easterly breeze, the eagles 
soar round and round high up in the air and scream 
frequently and loudly. 

A native told me that this was a sign of high wind 
coming, but I do not think it is of any more significance 
than an indication of the fine breezy weather as afore- 
said. 

The nest of the fish eagle is a conspicuous structure in 
the fork of a large tree. In October 1910 I saw a bird 
carrying in its talons a mass of building material up to 
the chosen nesting place. 

A certain large " Muvule " tree at Jinja was in use as 
a nesting place in 1914, and I found it still in use in 
February 1919, so that these birds would seem to choose 
the same spot year after year. 

The fully fledged young bird has a rather untidy 
appearance, its dark blackish plumage being irregularly 
spotted with dull white, and it only gradually acquires 
the magnificent snowy breast of its parents. The young, 
two in number, remain at the nest long after they have 
begun to fly, and are apparently driven away by the 
parents to look after themselves. At least this is the 
interpretation I put on what was seen on Kerenge Island 
in January 1919. Two adult birds were soaring round and 
round, and a third, in immature plumage, was apparently 
objectionable to them, for they kept swooping down and 
obviously trying to drive it away, yet not really en- 
deavouring to hurt it, and desisting from their attacks 
when it went a sufficient distance away. 

Another fish eating bird of prey is the common Osprey, 
but I have unfortunately nothing particular to say about 
it. The natives call it " Makwanzi," and a nest photo- 
graphed on the small Islet of Wavuziwa in January 1919 
was attributed to this bird. 

After the fish eagle the most conspicuous bird of prey 
on the islands is a brown, yellow billed Kite, " Akamunyi " 

12 



162 BIRDS 

{Milvus oegyptius parasitus), which is really extremely 
abundant. It was noticeable that the hiUs on certain 
islands, such as Kizima, always had a number of kites 
soaring over them, and it seems probable that the small 
area of heated lands surrounded by cooler water caused 
a continual up-current of air on which it was easier for 
them to soar. 

Their shrill, quavering cry is very characteristic and 
quite pleasant to hear. I think there are in proportion to 
area many more kites among the islands than on the main- 
land, at any rate the cry is not nearly so often heard at 
Entebbe or Jinja. Possibly this is because they are in a 
manner scavengers of the surface of the lake, and will 
swoop down and pick up small fish, or dead fish mangled 
by gulls, or other objects floating on the surface. But 
their appetites are all embracing. A grass fire will attract 
numbers of them, as well as of other birds, who sail round 
and round ready to pounce on grasshoppers and other 
insects fleeing before the flames. 

When winged termites swarm out of the ground in 
times of rain, kites speedily collect and circle round and 
round, catching the feebly flying termites in their feet. 
It is pretty to see one while on the wing stretch his foot 
forward and take the food from it with his beak in an 
easy, leisurely manner. The kite is not above trying to 
rob other birds of their prey, and will swoop down upon 
one in the endeavour to make it drop the fish which it 
has picked up for itself. 

Another smaller kite, known as " Ma'ga " by the 
natives {Elanus ccendeus), is quite common on certain open 
grassy islands. It is of a soft dove-grey and white. Its 
habit of hovering vertically over one spot with rapidly 
beating wings deceived me into thinking it was a species 
of kestrel, but I was put right by Mr. C. F. Belcher. While 
in camp at Jinja in 1910 I used to watch these birds 
carry the mice which they had caught on to a certa'-n 



HAWK AND CHAMELEON 163 

tree in front of the tent, and noted that they usually 
pulled out the viscera and let them drop to the ground 
below. 

A fairly large grey bird that may have been a buzzard 
was noted at Jinja under rather peculiar circumstances. 

I was walking along a path thickly bordered with 
castor oil bushes, when I heard a great fluttering coming 
from one, and saw a large grey hawk hanging by its feet 
from something yellowish on a stem of the bush. It 
appeared as if the bird had caught its feet in a tangle of 
creeper, and I went up to release it, wondering how I 
was going to avoid its sharp bill. 

When I approached within a few feet the hawk suddenly 
flew away, leaving a yellow object hanging from the 
branch. Only when a bright red drop slowly trickled 
down did I realize that the object was a chamseleon. 

The hawk had pounced on it and was trying to drag it 
from the branch, but the chamaeleon had such a firm grasp 
with its prehensile tail that all the flutterings of the bird 
had not succeeded in dislodging it. However, the grip 
of the talons had so injured the chamaeleon that it died 
almost immediately, so that the bird would have been 
able to carry it off in the end. 

I examined the stomach contents of the chameeleon and 
found a small snail and remains of orthopterous insects, 
probably tree dwelling Locustidae. 

A propos this observation, it may be said that the small 
brown lizards that run about on the grass roofs of native 
huts appear to be a desirable food, for one often sees 
birds of prey swooping down on them. 

I once saw a large cock peck at one till it was disabled 
and then swallow it whole, a disgusting sight ! 

Owls. — The cries of two species of owl are very familiar. 
One is a melodious quaver, heard on moonlit nights, 
the other a deep soft " Hoo-hoo," probably uttered by a 
big "long eared" owl {Bubo lacteus). During the day 



164 BIRDS ^ 

time one often hears quite a different noise proceeding 
from a thick shady tree, obviously emanating from an 
owl, bub whether from the latter sj)ecies or another I 
cannot say. 

As with other groups of birds, notable absentees from the 
islands may be mentioned among birds of prey. Vultures 
were never seen, but this is perhaps what might be expected 
from the absence of game. The beautiful Bateleur eagle 
{Helotarsus ecaudatus), so noticeable on the mainland, was 
either absent or so scarce on the islands that I cannot 
remember having seen it there. 

Another fine species, the Black and White Crested 
Eagle {Spizaetus coronatus), known to the Baganda as 
" Wonzi," was only very occasionally seen. I first became 
acquainted with this handsome, fierce looking bird at 
Jinja, where its rather weird scream was often heard, 
and the bird was often seen to perch on the summit 
of a dead tree. 

The next family to be mentioned is that of the Parrots, 
about which I have not much to say, since I have only 
met with one species on the islands. This is curious, 
because at Entebbe and Bukakata and Jinja may be seen 
quite commonly one of the small green parrots with yellow 
shoulders. 

The well known grey parrot with red tail occurs on 
many of the larger forested islands, and its discordant 
shrieks were familiar. At daybreak and eventide they 
fly to and from their favourite feeding grounds in small 
flocks, and, like no other bird, chatter and whistle con- 
tinually as they go. Often one hears the well known 
noises high overhead before the birds have come into 
view. 

On Sanga Islet one day, there were some parrots 
feeding in the trees which took alarm and flew off as 
I walked underneatli. One of them gave a call which 
seemed to be an imitation of the monkey's alarm, the 



PLAINTAIN EATERS 165 

only example I can cite of a wild parrot copying other 
sounds. 

After the parrots come the Plaintain Eaters {Muso- 
phagidae), one of which {Musophaga rossae), known to the 
natives as " Fulungu," is one of the loveliest birds of 
Uganda. 

Somewhere about the size of a rook, but with much 
larger tail, this bird has deep purplish blue plumage 
with bright crimson patches on the wings, making it 
very conspicuous when it flies. It also makes itself 
conspicuous by its voice, for it is a noisy bird. A company 
of them will be heard apparently working themselves up 
to concert pitch, with short cacklings and gurglings, 
and then they suddenly all burst out together into loud, 
not unmusical cooing in a most pleasing manner. 

These birds are typically forest species, and are only 
seen where the forests are of some size, so they do not 
occur .on the smaller islets. 

Another species of very different appearance has much 
less gaudy plumage, being ashy grey, and showing patches 
of black and white on wings and tail when flying : probably 
it is Schizorhis. I often used to see a pair on Damba, 
where a marshy piece of shore had ambatch trees in flower 
that were highly attractive to these birds, w^hich were 
frequently seen pulling off the bright yellow flowers and 
devouring them. 

They, like the Musophaga, are noisy birds, and attract 
attention by their vociferous habits. 

One, presumably the cock bird, used to do what airmen 
call ." stunts " in the air, shooting vertically upwards and 
then dropping headforemost to join the other in the 
ambatch bush, with the accompaniment of loud cackling 
and croAving noises. Though so frequently seen in the 
ambatch bushes they always came from the forest, to 
which they retired when alarmed. 

The Lark-heeled Cuckoos or Coucals (Centropidae) abound 



166 BIRDS 

among the forests and patches of bush on the islands, but 
there are differences from the mainland in the propor- 
tions of the species. Their liquid gurgling notes, descend- 
ing and ascending again, have earned for them the native 
name " E'tutuma " and the English " Bottle Bird," the 
latter name because of the resemblance to the noise 
made by water being poured *out of a bottle with long 
narrow neck. 

Generally speaking, they are skulking birds, avoiding 
the open and concealing themselves among bushes, under- 
growth or papyrus, whence they fly heavily away with 
broad tail outspread. 

Heavily built, with large stout beaks, they cannot be 
considered attractive, though their rich brown, black 
and white or yellowish plumage is often beautiful. 

A species that was unusually abundant on Bugalla 
(Ceuthmochares ceneus) was of a dark greenish black all 
over, with the large bill bright yellow. Its note also was 
somewhat different from that of most coucals, being a 
harsh screech. I saw one fly away from a clump of bush 
with a butterfly held in its beak, but another that I shot 
had fed largely on hairy caterj^illars, as is the cuckoo 
custom. So much less common is this species elsewhere 
that I cannot remember having noticed it on other islands 
or the mainland. On the other hand, a certain large 
species, whose deep booming call is heard in mainland 
forests, was absent from the islands. 

Next to be mentioned are the Cuckoos. I am familiar 
with the notes of only two species of cuckoo on the islands, 
one of which {Cuculus solitarius) is very common and from 
its cry has been named " Sekoko " by the natives. The 
frequently reiterated call is a descending sequence of 
three notes, and during the rainy season is very noticeable, 
the bird sitting perched in a conspicuous place and calling 
again and again as does our English species. 

Though its colouring is different from that of the latter 





VIEW FROM CAMP ON KOME, LOOKING EASTWARDS. 
Damba Isle in far distance. 




VIEW TOWARDS BUVUMIRA FROM BUGALLA CAMP. 



To face p. iC6. 



CUCKOOS— BARBETS 167 

bird, the Sekoko is very obviously a cuckoo, both when 
seen perching and on the wing. It seems to call only 
during the two periods of greatest rainfuU, when it is 
presumably breeding. 

The other cuckoo whose note is familiar is the 
" Ekirimululu," (Chrysococcyx caprius or C. klaasi), one 
of the bronze cuckoos, a small species, metallic green 
above and whitish beneath. The native name, like so 
many others, is doubtless onomatopoeic. 

Another group, the Barbels, is strangely unfamiliar on 
the islands. One of the commonest of all, the little Copper- 
smith {Barbatula leucolaima), has never been heard on 
any island, although its monotonous " Tonk-tonk-tonk " 
can be heard all day long in the Entebbe gardens. Their 
absence from the islands was made more noticeable when 
in January 1919 I went across to the Kyagwe coast from 
the camps on Kerenge and Wema. Almost immediately 
one landed on the mainland one heard the well known 
metallic note in the forest, together with the notes of 
other birds not present on the islands. 

Larger, red breasted barbets have not been noticed 
either there, but they do not force themselves upon one's 
attention as does the persistent coppersmith. 

The next family, Coliidae, is easily dealt with, for they 
are absent from islands that have been visited, and since 
I was quite familiar with them at Jinja before I first went 
on to the islands, they would certainly have been seen or 
heard, for I know the twittering sound they make very 
well ; it is constantly heard in the gardens at Entebbe. 

We now come to the Rollers and their allies. Rollers 
themselves may be dismissed in a few words, for I never 
saw one on the islands. I had seen them at Jinja in 1910, 
and thus knew their appearance, and, having seen them 
in numbers during the East African campaign, was on the 
look out for them when I returned to the islands in Decem- 
ber 1918, but the result was the same. 



168 BIRDS 

This seems very curious, and I should like a practised 
ornithologist to confirm or contradict the statement. 

Other members of the sub -order now being considered 
are the Hornbills, one of which {Bycanistes subcylindricus) 
is one of the most characteristic birds of the Uganda 
forests, and abounds on the islands. This great black 
and white bird with its curious bill is known to the natives 
as " E'nga-nga," from its nasal, raucous cry. It is a noisy 
and conspicuous creature, clumsy and grotesque in its 
habits, and is perceived both by ear and eye from a 
considerable distance away. The flight is heavy, and the 
beating of the wings for a few strokes is followed by a 
pause during which the bird sails through the air with 
wings outspread, making a loud roaring noise presumably 
owing to the arrangement of the feathers. When an 
" E'nga-nga " flies past, I am always reminded of the noise 
made by a puffing locomotive as one hears it coming 
from a distance, the noise rising in pitch and getting louder 
as the engine approaches, falling and dying away as it 
disappears in the distance. The bird also frequently 
screams while flying, as if to let all the world know where 
it is. 

I believe that there is an explanation of this noisy 
flight as aposematic — the conspicuous bird makes itself 
perceived by ear as well as eye in order that enemies may 
recognize it. It is of interest that Dr. G. A. K. Marshall 
records that the flesh of an allied species was found dis- 
tasteful by a mongoose, and that natives look on it as so 
poisonous that it will render water unfit for drinking if 
the carcase falls into a stream. ^ The subject of aposematic 
flight will be brought up again in the chapter on 
the Hymenoptera in connection with the fossorial Pom- 
pilidae. 

Foolish looking as is the " E'nga-nga," it is surpassed 
in that respect by a more slenderly built smaller species, 

1 Proc. Ent. Soc. Lorid., 1902, pp. 378-9. 



KINGFISHERS 169 

without any casque on the bill, whose appearance always 
fills me with resentment that it should exist at all 
{Lophoceros melanoleucus). It has a floppy flight, rising 
and falling as it flaps its way along with inane, shrill 
cries. Its dull whitish and black plumage has not the pure 
tints and arresting appearance of the " E'nga-nga," and 
indeed I find it difiicult to say anything nice about this 
bird. 

No other hornbills than these two species have been 
noticed on the islands. 

Next to be mentioned are Kingfishers, and it is curious 
that the natives have the same name for one very common 
black and grey spotted species as for Bee-eaters (" Mujolo "), 
but other kingfishers are known as " Akasimagizi." 

The " Mujolo " kingfisher (Ceryle rudis) is extremely 
common along the lake shore, where shallow water with 
sandy bottom provides good fishing grounds. Its habits 
are somewhat different from those of other species, such 
as our familiar one at home, which plunges into the water 
from some commanding perch. Ceryle rudis hovers over 
the water, head hanging down with beak pointing vertically 
to the surface, wings rapidly beating like those of a kestrel. 
Often it has to wait a long time, and change its position 
till some unwary little fish comes near enough to the 
surface, when the kingfisher plunges in head foremost and 
secures it. This bird is rather vociferous, and its twittering 
cry is very often heard as it flies across the water, keeping 
close to the surface. Another species of Ceryle {C. maxima) 
is scarce, and of solitary habits, very much larger than 
any other kingfisher on the islands. It lurks among 
bushes overhanging the water, and is usually first noticed 
flying away when it has been disturbed, uttering a loud 
unmusical bleating cry. 

Beautiful little species of the genus Ispidina (? picta) 
are often seen among the rushes growing in shallow water 
or on low t^vigs of ambatch trees just above the water, 



170 BIRDS 

whence they plunge in to secure their prey. Their feeble 
little piping note is much like that of our English king- 
fisher, but though very soft it often directs one's attention 
to these lovely little birds as they dart past. 

About the size of a sparrow, but, of course, of different 
appearance, with short tail and enormous bright red 
beak, these birds have lovely orange and deep blue 
plumage. 

Natives say that if one comes near their house it is an 
omen that some one is going to die j and it was a curious 
coincidence on Bugalla that when one of my canoe-men 
was ill vrith. pneumonia one of these birds was frequently 
noticed in the camp, although I had not seen it there 
before. 

I did not know the superstition until some time after 
this. Fortunately the canoe-man recovered ; perhaps if 
he had known the bird of evil omen was there the issue 
would have been less satisfactory ! 

Another kingfisher, of different habits, is Halcyon 
senegahnsis, whose large beak and legs of crimson contrast 
beautifully -^-ith its sky blue wings and back and grey 
under surface. This is a forest or bush frequenting species 
which has given up a fish diet in favour of large grass- 
hoppers. 

Sitting on a branch it watches the grass for movements 
and then pounces down on a " Janzi " grasshopper which 
it carries back to the perch. Here the unfortunate bulky 
insect is banged against the branch until it is in the right 
condition to be swallowed whole. This kingfisher has a 
loud and cheerful cry. It commences with a sharp high- 
pitched note which is followed by a churring descent down 
the scale, and on a bright sunny morning this familiar 
sound may be heard over and over again. 

I saw an interesting little incident on Kerenge in 1914. 
One of these birds was angrily scolding on a perch which he 
considered to be his, but the justice of the claim was 



KINGFISHERS— BEE-EATERS 171 

disputed by one of the Paradise flycatchers, which kept 
trying to get at the kingfisher from behind. The other, 
however, spun round on the perch just as quickly so as 
always to face the angry flycatcher. 

But at length another flycatcher came up, and the 
kingfisher made off, thinking discretion the better part of 
valour. 

Another species of Halcyon may here be mentioned on 
account of its remarkable absence from the islands. This 
duU mottled greyish bird, H. chelicuti, is abundant both 
at Jinja and Entebbe, where its " cheer-oh " cry may often 
be heard in chorus, and yet I never heard it on the islands, 
although Van Someren gives " Sesse Isles " as a locality 
for this species in his check list.^ 

The absence of the insectivorous Rollers seems to be 
compensated on the islands by great abundance of their 
allies the Bee-eaters. These graceful birds, known to the 
natives as " Mujolo," soon attract attention from their 
habit of perching on the tip of a dead bough in a com- 
manding position and swooping down on their prey, 
returning with it to the same perch. Two species, Merops 
superciliosus and Melittophagus meridionalis, became very 
well known, and the liquid twitter of the former was one 
of the most familiar bird sounds. 

When a blustery wind is bringing up storm clouds, this 
bird often soars overhead innumbers, braving the buffeting 
of the gusts of wind and possibly catching the insects that 
are driven before the storm. 

Melittophagus is found more often in grassy places, or 
at the edge of the forest perched on an especially tall 
stem of grass or rush. It keeps nearer to the ground than 
does its larger, long-tailed relative. Neither of these birds 
is brilliantly coloured, but their green, yellowish, and 
brown hues are very pleasing, and their long bills and 
graceful shapes give them a very attractive appearance. 

1 The Ibis, 1916, p. 244. 



172 BIRDS 

I noticed particularly that Dragon-flies are a very favourite 
food of both species, as well as the bees and other 
Hymenoptera on which they are well known to feed, 
which were constantly found in the stomachs when I 
was searching for evidence that the Tse-tse fly was eaten 
by birds. (See vol. xiv of Sleeping Sickness Reports of 
the Royal Society, 1913, pp. 15-16.) 

Stomach Contents of Bee-eatees. 
Merops superciliosus. Mclittophagus meridionalis. 

1. Mainly dragon flies. 1. Mainly dragon flies. 

2. Dragon flies and honey bees. 2. Dragon flies and honey bees. 

3. Dragon flies and honey bees. 3. Dragon flies. 

4. Dragon flies and honey bees. 4. Dragon flies. 

5. Dragon flies and honey bees. 5. Dragon flies and small beetle 

(Lamellicorn). 

6. Dragon flies and honey bees. 6. Winged ants and one small 

dragon fly. 

7. Dragon flies and honey bees. 7. Dragon flies and bees. 

8. Dragon flies and honej^ bees. *8. Winged ants only. 

9. Dragon flies and honey bees. *9. Winged ants' and one Agrionid 

dragon fly. 

10. Dragon flies and honey bees. *]0. Winged ants and a small species 

of Chrysididae. 

11. Dragon flies and honey bees. *11. Winged ants. 

12. Dragon flies, bees, and a 

Beloyiogaster wasp. 

27. Dragon flies. * These were all shot on the same 

28. Dragon flies. day (11-12-11). 

29. Dragon flies and bees. 

30. Dragon flies and bees. 

31. Dragon flies and bees. 

32. Dragon flies. 

33. Dragon flies and bees. 

34. Caterpillars and young Mantidae. 

35. Eleven bees. 

36. Twelve bees, one wasp, one 

dragon fly. 

37. Twelve bees, one male Stink 

ant (Paltothyreus). 

Frequently one would hear a loud tapping noise, and 
looking up would see a bee-eater with a large dragon fly 
in its beak banging it against the perch on which it sat, 
finding the long body and wings rather unmanageable, 
for they swallow the dragon flies wings and all. 



NIGHTJARS 173 

Butterflies appear to be eaten by Melittophagus, for 
I have found on the ground, under a grass stem on which 
one had been sitting, wings of the Httle yellow Terias 
butterflies, although I have not actually witnessed the 
capture in this case. 

Another group of birds allied to the Rollers may be 
dismissed in a few words, namely, the Wood hoopoes 
{Irrisorinae), for I have never met with them on the 
islands, and first saw them when on active service in 
German East Africa. 

Such noisy and conspicuous birds could hardly have 
escaped notice had they been on the islands, and when I 
returned in 1918 they were watched for, but never seen. 

The family of Goatsuckers, or Nightjars, is represented 
on the islands by a species of Caprimulgus, whose native 
name is " Olubugabuga," presumably an attempt to 
reproduce one of the noises that it makes. On moonlit 
nights, when owls are also heard, these birds keep up a 
continual " Tok-tok-tok-tok-tok," varied occasionally by 
the melodious cry from which their name is derived. 

The bird itself is often flushed during tday time from its 
resting place in places that may sometimes be quite open 
and fully exposed to the hot sun, or sometimes shaded and 
among bracken. There is nothing about the bird to call 
for remark, unlike the East African species with long 
floating plumes, which has not been met with on the 
islands. 

It is, of course, highly probable that there is more than 
one nightjar on the islands, but I am familiar with only 
one cry. 

We now come to the great order of Passeriformes, 
embracing large numbers of small birds, which I must 
perforce pass over in silence, not being sufficiently familiar 
with the comparatively inconspicuous species. 

Certain species, however, call for notice, and first 
among them are the Flycatchers (Muscicapidae), of which 



174 BIRDS 

two species particularly attract attention. The first, 
Tchitrea emini, is illustrated from a photograph which 
shows well a very beautiful feature, namely, the long 
snow white tail plumes assumed by the cock bird in 
the breeding seasons. The rich chestnut brown, black 
and white plumage of body and wings is set off by 
slaty blue black crested head, and it is a delight to 
watch the vivacious bird, as it is for ever flitting among 
the branches and chasing another from perch to perch. 
The insistent call, quite impossible to describe, loud and 
ringing, was the first bird note to be heard in the early 
morning from the forest around the camp on Bugalla. 
As soon as the darkness began to lighten these delightful 
birds were awake and filled the forest with their call. 
The native name for this bird is " Kunguvu." When I 
left Bugalla I went home, but the memory of the call 
there has persisted clearly, and I am sure that the Bugalla 
race of the Kunguvu has its own call, i.e. a geographical 
race is being developed. The bird is plentiful enough on 
many other islands ; indeed, it is one of the species which 
is far more abundant on islands than on the mainland, 
but nowhere has its call quite the same character and 
finish as on Bugalla. I particularly noticed this during 
the tours of 1914 and 1918-19, during the letter of which 
several forests on the mainland coast were visited. 

It is not surprising that the birds on a large island such 
as Bugalla should be forming a local race — they are 
confined to the forest and do not take long fiights. 

One was never tired of seeing the cock bird pursuing 
the hen among the branches, excitedly calling to her, 
with snow white plumes trailing in the air as he flitted 
from branch to branch. The nest is a small shallow cup- 
shaped structure ; I have seen it fastened to the end of a 
dependent creeper, quite exposed in the open, but in such 
a position that nothing without wings could reach it. 
The hen bird was fully exposed as she sat. 




KUNGUVU " FLY-CATCHER {tCHITREA EMINl) 
Foot-rule on right. 




.NEST OK CROCODILE. 
The marks of the mother's body and tail on the sand can be plainly seen. 

To face p. 174V 



FLYCATCHERS— SHRIKES 175 

Another delightful little bird that soon became very- 
familiar on Bugalla was the black and white flycatcher, 
with bright red wattle over the eye, probably Platysteira 
jacksoni, whose call note is very characteristic. Two 
birds were often heard calling one to another. The first, 
with high-pitched pipe, would sing " How are you ? " to 
which the other responded, " I'm pret-ty well, thanks." 

By whistling the first phrase I could often get the 
answer and bring the bird near. Like Tchitrea this bird 
seems to be forming a local race on Bugalla, for the call 
elsewhere is not exactly the same, although one can recog- 
nize it as coming from the same bird. 

It is not so much a forest frequenter as Tchitrea, 
being found more among the clumps of bush and copses 
that make the park like country on the larger islands. 

A third very pretty little flycatcher {Elminia longicauda) 
is worth noticing here, because I have not seen it on the 
islands, save once on Kizima, though it is often seen in 
the gardens of Entebbe. It is a light blue bird which has 
a habit of spreading out its tail fan wise, and hence attracts 
one's attention. 

Shrikes are noteworthy because several species familiar 
in the gardens of Entebbe and Jinja have never been 
seen on the islands. Conspicuous among these is the 
beautiful black bird with scarlet breast {Laniarius 
erythrogaster), pairs of which haunt Hibiscus bushes, whose 
red flowers exactly correspond with the breast of the bird. 

They have a call note which may be crudely represented 
by " What-ho. " This is uttered by one, and simultaneously 
the other of the pair makes a harsh scolding or churring 
noise, not at all musical. It is curious that many shrikes 
have this habit of uttering a joint call ; for instance, the 
long tailed black and white species, whose very musical 
notes I have often heard on mainland but never on an 
island. 

A brown shrike (? Pomatorrhynchus) that was shot on 



176 BIRDS 

Damba Isle was found to have eaten only grasshoppers 
in two cases, in the third grasshoppers and one beetle. 

Very noticeable absentees from the islands are the black, 
fork-tailed, insectivorous Drongos (Dicruridae) , which were 
never met with there. The first ones I ever saw were on 
the frontier between German East Africa and Uganda 
in the early days of the war, and later in various parts of 
German East Africa they were seen abundantly, so that 
I became thoroughly familiar with them. When I returned 
to the islands in 1918 for about three months, I should 
therefore certainly have seen Drongos had they been 
present. It has seemed to me during my wanderings 
that where Drongos were abundant Bee-eaters were scarce, 
and since Bee-eaters appear to be unusually plentiful on 
the islands and Drongos are absent, it is possible that these 
birds of similar habits take each other's place to a certain 
extent. 

The Starling family is also notable for the absence of 
conspicuous species from the islands, viz. the Glossy 
Starlings, which certainly could not escape notice. These 
birds have the typical shape and noisy habits of our 
home species, but their dark plumage is resplendent with 
metallic purple and green. Their harsh voices are very 
familiar at Entebbe among the tall trees, and their noisy 
flight also renders them conspicuous to the ear. Directly 
I entered the forests on the Kyagwe coast opposite the 
islands where I was working, these noisy birds attracted 
attention, so that I am quite sure they do not exist on any 
island I have visited. 

Weaver Birds (" Endegeya ") are abundant among the 
ambatches which overhang the water ; but some species, 
that make their nests in colonies on large trees on the 
mainland, so that the noise of them at a little distance is 
like the sound of a waterfall, have not been met with 
on the islands. 

Neither have I seen the Bishop and Widow finches, 



FINCHES—SUNBIRDS 177 

beautiful brightly coloured birds, which could hardly 
escape notice. 

The Fringillidae, or Finches, would doubtless be of much 
interest to an ornithologist, but I have little knowledge, 
and less to say, about them. Noteworthy varieties on the 
islands are Sparrows, " Enkazalugya " {Passer griseus), of 
which very few were ever seen ; possibly the absence of 
mankind has something to do with this. Another notable 
absentee is a curious rotund little grass finch, which is 
abundant at Jinja and Entebbe. The cock bird when 
adult is black and white, and has very long floating tail 
feathers which appear to hinder his flight. He flits for a 
short distance over the grass with an up and down motion, 
uttering feeble chirps, accompanied by a flock of brown, 
insigniflcant looking individuals, which I always took for 
females. Mr. C. F. Belcher, however, tells me that most 
of them are immature males. 

A very common and pretty little flnch is often seen 
hopping about on the ground at Entebbe and Jinja ; 
of a reddish pink or old rose colour, it is often nicknamed 
the " animated plum." It is about the size of a red plum, 
and agrees with one very well in hue. 

Another species, much like it in habits and shape, is 
grey and blue. Neither of these have been met with on 
the islands. 

The pretty little Sunbirds (Nectarirdidae) are abundant 
on the islands, though I know not how many species are 
found there. On certain very small islets they and wagtails 
are the chief part of the bird fauna, but this depends upon 
whether their favourite food plant is there. This is a 
labiate, which sends up tall stems bearing scarlet flowers 
arising from a knob. These knobs are set at intervals 
up the stem, and when the flowers are withered and the 
seeds develop are unpleasantly spiky to knock against. 

Wherever a cluster of these plants grows, a sunbird 
is sure to be seen clinging on to the stem and thrusting 

13 



178 BIRDS 

its slender bill down the tubes of the flowers one after 
another. 

There is no doubt, however, that they also eat insects, 
or at any rate spiders. I have seen one hovering in front 
of a web spun amongst tall stems of grass and delicately 
picking o£f the spider that sat in the centre of it. 

On the other hand, a sunbird was once found hopelessly 
entangled in the strong sticky threads of a web of a Nephila 
spider, the sheets of whose webs are so unpleasantly 
abundant on many of the islands. Fortunately, I was 
able with a stick to reach up and set the bird free. The 
cock bird is a beautiful little creature, the prevailing hue 
being rich metallic green, but different species have the 
throat and breast of brilliant scarlet or other bright 
colours ; the hen bird is dull brown or grey. As is usually 
the case with brilliantly coloured birds, the song is not 
musical, but it is quite a pleasing, lively little twitter. 

They are pugnacious birds, and may often be seen 
chasing each other with angry scoldings, and I have 
watched them chasing away the huge Carpenter bees from 
the attractive flowers of a bush. 

Ths Warblers must be passed over, since I have no 
ornithological knowledge of them ; but there is one 
species that is very familiar, since it inhabits the low 
bushes in the forest and its sharp chirp is heard every- 
where. It has the appearance and manner of a wren, 
with short upturned tail, and is constantly in evidence 
climbing about among the branches on which it hunts for 
sedentary insects, or angrily chasing away another which 
is trespassing on its feeding grounds. It is, I think, 
more abundant on the islands than on the mainland. 

The Thrush family deserves mention on account of the 
fine songster Cossypha, (possibly heuglini,) or Robin Chat 
(E'nyonza), which abounds in the forests. It is a handsome 
bird, but one seldom seen, as it is of retiring habits and 
rarely leaves the sheltering bushes. Occasionally one gets 



COSSYPHA 179 

a glimpse of its bright orange under side, with dark back 
and white streak on the head. Its mellow voice reminds 
one in a way of the blackbird ; but it has a unique method 
of singing as if for its own enjoyment, quietly and in a 
thoughtful way; there is no "fine careless rapture." It 
is an extraordinarily clever mimic, and in the evenings 
one can hear it copying the notes of fish eagle, owl, blue 
kingfisher, cuckoo, and doubtless many other birds as 
well, introducing the well known notes into its own steady 
flow of music. 

Song thryshes, obviously closely allied to the English 
songster, are abundant at Entebbe, where their music 
brings up memories of home ; but they are only occasion- 
ally heard on a few of the islands. Kibibi, Kiuwa and 
Kizima were noted as having these birds. 



CHAPTER IX 

REPTILES AND FISH 

A BOOK about life on the Victoria Nyanja may reasonably 
be expected at least to mention the crocodile, known to 
the natives as " E'gonya," 

His scarcity was what one noticed most, for which a 
reason will be suggested later. One had read so much 
about crocodiles in tropical rivers lying thickly on 
the mud, and in great numbers in the water, that one 
had expected to see the same in the lake. This was far 
from being the case, and it soon became clear that one 
or two could usually be seen on any day frequenting 
the same haunts, but that it was possible to go long dis- 
tances and never see a crocodile, and young specimens 
are rarely seen. 

Their favourite haunts are of two kinds — a stretch of 
coastline fringed with rushes and reeds growing in shallow 
water, wherein they lie with only the top of the head 
and scaly ridge of the back and tail showing, or an open 
shore of rock or sand on which they warily bask. Near 
my camp on Bugalla the northern bay furnished a haunt 
of the first Idnd, and a large crocodile could nearly always 
be seen there. Ngamba and Tavu Islands provided 
rocky basking places, and a favourite large rock on the 
east side of Tavu was seen, whenever visited, to have 
one or more crocodiles basking on it, and on one occasion 
seven were seen there, which was the greatest number 
ever seen together. It was amusing to see these huge 

180 



CROCODILES 181 

antiquated reptiles take alarm as soon as the canoe drew 
near, and plunge headlong into the water ; they were 
always off before one got near enough to take a photo- 
graph. 

It seems strange that such a huge and well defended 
creature should be so nervous. On the only occasion 
when I have got within camera range, of course I had 
no camera with me. On the northern coast of Ngamba 
I was pushing my way through rocks and dense bushes 
Avhen I suddenly heard, apparently right in front of my 
feet, a horrid noise, half hiss, half snarl. Hastily stumbling 
back, I saw I had nearly stepped on the head of a large 
crocodile lying on the ground. I remained still and 
watched, noting Tse-tse fly feeding on him, and wondered 
why he did not, as usual, rush headlong into the water. 
Before going away I threw a lump of rock on to his back, 
but that did not move him ; he merely hollowed his back, 
raising head and tail in the air, and with mouth wide 
agape gave a sort of bellow. Possibly he was sick or 
was exhausted from fighting, for there was an ulcerated 
wound at the base of his tail. On the same island at 
a later date I saw another large crocodile with a similar 
wound, but on the opposite side, and wondered if this 
had been the partner of the duel. 

Crocodiles deposit their eggs in a hole scooped in a 
dry sandy beach ; these are afterwards carefully covered 
over to a depth of about a foot, and one often sees the 
imprint of the body of the mother on the soft sand, even 
the pattern of the scales on the belly being clearly shown, 
so that it appears that the parent returns to visit the 
nest, though she does not seem to be very successful 
in protecting the eggs, as will be seen later. 

During 1914 numbers of nests were found, of which 
a list is given below : the number of eggs varies little, 
averaging sixty in one nest. No evidence was obtained 
that more than one crocodile lays eggs in one nest. 



182 



REPTILES AND FISH 



The period required for development is stated to be 
twelve weeks. ^ 



Where Found. 


Date. 


Number 
of Eggs. 


State of Development. 


1. Marida . . 


Feb. 21 


58 


/33 almost ready to hatch. 
\25 shrivelled and undeveloped. 


2. Masovwi 


March 6 


59 


Embryos about i grown. 


3. Kizima . . 


March 11 


60 


Embryos about J grown. 


4. Bulago . . 


March 14 


64 


Embryos about J grown. 


5. Tavu 


June 17 


60 


Freshly laid. 


6. Kimmi . . 


June 30 


59 


Laid between June 23-30. 


7. Kimmi . . 


July 6 


69 


Laid between June 30-July 7. 


S. Bulago . . 


July 24 


66 


] 


9. Bulago . . 


July 24 


57 


>Laid between July 17-24. 


10. Bulago . . 


July 24 


76 


J 


11. Tavu .. 


August 18 


65 


1 


12. Tavu 


August 18 


48 


>Laid between July 30-August 18. 


13. Tavu 


August 18 


38 


J 



Note. — Only in the first case was every egg examined, and the number 
that had failed to develop is surprising. In view of this fact it is to be 
regretted that subsequently only a few from each nest were broken open. 



The Monitor Lizard. 

By far the most notable reptile on the islands is the 
enormous Monitor Lizard {Varanus niloticus), called by 
the natives " Enswa-swa." It is of a dull grey colour 
speckled with yellow, and its long tail is flattened from 
side to side for swimming. This fine creature may 
measure almost six feet from nose to tail tip. It 
is never found far from the water, into which it rushes 
headlong when disturbed, so that its panic-stricken flight 
is very often heard as one pushes through the dense 
vegetation bordering the shore. In the water the Enswa- 
swa swims with vigorous strokes of the flattened tail, 
and may often be seen lazily sculling itself along with the 
top of the head just above the surface. When alarmed 
it hastily dives, and can remain under water for a 
^ Gadow, Cambridge Natural History, vol. Reptiles, p. 465. 




A CANOE-MAN AND AN " ENS\VA-S\VA " JUST CAUGHT. 



To face p. 182. 



VARANUS 183 

surprisingly long time. Like the crocodile, Varanus has 
favourite basking places on the rocks, choosing preferably 
a place where ferns grow, on which it lies ; but curiously 
enough if one is tethered in the sun it dies, apparently 
from exposure, in an hour or so. 

Crocodiles are, as has been said, scarce among the 
islands, but Varanus is very abundant, and must have 
increased in number very greatly since the removal from 
the islands of the natives, among whom skins of Enswa- 
swa are in great request for making the long narrow 
" Engabi " drums, which are beaten by the hand at con- 
vivial gatherings or weddings. But though the Enswa- 
swa are abundant enough, one does not often meet with 
their nesting places ; the only three that I ever saw were 
a sandy patch of open ground on the north side of Kimmi 
Island, where burrows and fragments of old eggshells 
were found, a regular warren in sandy soil on Busiri, 
and a- similar place on the south end of Sindiro Isle. 
Occasionally I saw very young Enswa-swa close to the 
water sunning themselves on little branches like any 
other lizard, but I do not think the adult climbs up trees ; 
it appears to be an instance of the losing by an adult 
of an ancestral habit retained in youth. A curious 
inverted ratio was found to exist between the members 
of crocodiles and Enswa-swa on any particular islet : during 
the tour at the commencement of 1914 it- was noted that if 
many Enswa-swa were seen there were very few crocodiles, 
and vice versa. Thus, on Tavu Island, where more 
crocodiles were seen than on any other island, Enswa- 
swa were exceptionally scarce ; this was verified by many 
visits and work on the island. On the other hand, when 
Rumfua was visited, during the examination of its shores 
from a canoe five Varanus but no crocodiles were seen. 
It must be admitted, however, that Rumfua was only 
visited once. Isentwa was noted to have abundant 
Enswa-swa, but no crocodiles were seen there. Although 



184 REPTILES AND FISH 

it will be shown below that Varanus has a profound 
influence upon the number of crocodiles, yet it is not 
clear how the reverse can be the case. Varanus seems 
to enjoy a varied diet. The stomach of one was found 
to contain two slugs and the shell of an operculate fresh- 
water mollusc, and collections of shells of the large water 
snail Ampullaria are often seen on the shore broken on 
a rock as garden snails are broken by thrushes. ^ 

I have seen a young Varanus biting off the juicy lower 
part of the stems of rushes ; natives say they eat fish, 
and on one occasion when my boys were walking a little 
ahead on the shore, one of them saw an Enswa-swa run 
away from a piece of dead fish. On one occasion at 
Jinja a scnall bird that I had shot fell down almost on 
top of an unperceived Enswa-swa, who at once picked 
it up and ran away with it, shaking the struggling bird 
as a terrier shakes a rat. 

The most important food of Varanus, so far as man is 
concerned, is the egg of the crocodile, and there is no 
doubt whatever in my mind that the increase of Varanus 
on the islands since the depopulation must eventually have 
a powerful effect in reducing the number of crocodiles 
there. Thus on July 30, 1914, on Tavu Island, two 
crocodiles' nests previously noted there were found to 
have been disturbed ; holes had been dug and a crushed 
egg was lying on the sand. On Bulago Island, on 
August 1st, two nests previously noted were found 
ravaged and crushed eggs lay all round. At another point 
a nest of seventy-six eggs that had been found, freshly laid, 
on July 24th, had been absolutely cleared out and not 
one was left. In seven days eggs had been accounted 
for at the rate of eleven a day, which would seem to be 
more than one Enswa-swa could accomplish ! In fact, 
no nest of crocodiles' eggs tvhich I visited a second time 

^ This may, however, be entirely the work of the open-bill stork. See 
Chapter VIII. 



VARANUS AND CROCODILE'S EGGS 185 

ivas found to have been left undisturbed. Though I have 
not actually seen Varanus devouring the eggs, there is 
no doubt of it from the tracks they leave in the sand 
all round and over the nest, and my friend Dr. Lyndhurst 
Duke told me that he had actually seen one digging 
away at a nest. It therefore appears that strict protec- 
tion oi Varanus against slaughter by natives should be an 
effectual method of keeping down the numbers of croco- 
diles. The importance of Varanus as a food supply of 
Glossina has been alluded to in the chapter on the Tse-tse, 

A fine large lizard of the family Agamidae is known 
as " E'konkomi " by the natives. It has a brightly 
coloured male partly sky blue, the female being grey. 
They particularly frequent open places, but prefer to 
have a large tree in the neighbourhood, up which they 
run when alarmed. The E'konkomi seems to feed very 
largely on ants, judging by the remains found in its 
excreta, and from the contents of the stomachs examined 
in several specimens. It has to a marked degree 
the habit that may be seen in many lizards, alternately 
raising and lowering the body between thfe fore limbs, as 
is done by a man lying prone on the ground in a common 
gymnastic exercise. I could never make out the sig- 
nificance of this habit, though I think it is developed 
to a greater degree in the male sex. 

Smaller, more slender lizards (Lacertidae) played on 
the roof of my tent, and from inside I could wateh their 
shadows as they scuttled about. It was most amusing 
to see them playing : one would stealthily creep up 
behind another and bite his tail, and then there would 
be a pursuit and a rushing about all over the tent. 

They would dispose themselves for the night some- 
where among the folds of the tied-back doorv/ay, and 
on one occasion I was awakened by hearing their well 
known pattering feet on the roof. Realizing that some- 
thing must have turned them out from their sleeping 



186 REPTILES AND FISH 

place, I lit a lamp and found that a column of the " Safari 
ant " {Dorylus) had directed its attention to that part 
of the tent, but fortunately for my night's rest they did 
not investigate my bed. 

The little grey Gecko, with discs on its toes enabling 
it to run upside down on ceilings and walls, was not seen 
in my huts on the islands, although common enough on 
the mainland ; but I do not mean to state that it did not 
exist on the islands. 



Tortoises. 

Like crocodiles, tortoises are less plentiful than might 
be expected. The numerous isles of varying size furnish 
abundant areas with marshy shore and shallow, rush- 
grown water, which appear eminently suitable for water 
tortoises, yet it was many months before I saw one — a 
flat, black, short tailed Species that wanders about near 
the water's edge. One species of land tortoise is occasion- 
ally seen ; the natives call it " Enfudu," a name that 
seems to carry with it a suggestion of blundering stupidity 
not altogether foreign to a tortoise. It is somewhat 
larger than the European species kept in gardens, and 
has a high domed shell, with the anterior and posterior 
portions of the ventral plate hinged so as to be capable 
of a little movement. I once found a specimen that had 
apparently been dropped from a height ; it was a large 
one, and the highest part of the dome of the shell had 
been fractured, a portion being depressed. It had probably 
been destined to be eaten by some bird of prey, which had 
been frightened away at my approach, for the blood on 
the wound was still fresh. So there may be, after all, 
some truth in the old legend which ascribes the death 
of a Greek sage to the impact of a tortoise dropped upon 
his bald head by a bird of prey, which mistook the shining 
cranium for a stone ! 



SNAKES 187 



Snakes. 



During one's wanderings through thick grass and 
among bush and rocks one frequently came across snakes 
hastily retreating as one ajDproached. 

It seems to be a fixed idea with some people that a 
snake's main object in life is to find a human being and 
bite him. I take the opposite view, that so far as man is 
concerned the snake is chiefly occupied with avoiding 
him lest he do the snake harm ! 

From the snake's point of view, what possible object 
can there be in wasting valuable poison by biting a huge 
creature who cannot be eaten, and could, even when 
mortally wounded, crush the life out of a snake before 
he dies ? So, hearing some heavy footstep come crashing 
through the grass, the wise snake departs as quickly as 
possible lest he be trodden upon. 

This is where a booted man has the advantage of a 
silent-footed native, who gives no warning, so that a 
snake half asleep, or languorous after a meal, or stupid 
and half blind owing to an approaching shedding of 
skin, suddenly finds a large animal almost on top of him, 
and strikes in a panic of self-defence. 

Once only I very nearly trod upon a large black snake, 
a species common on the islands, and reaching up to six 
feet in length. I was walking through very thick, high 
tussocks of grass, which made it necessary to go slowly 
and to lift the feet high. In the middle of one step, 
while my foot was in the air, the snake crawled out from 
a very dense tussock across the very spot for which my 
foot was destined. It was fortunately just not too late 
to put the foot down elsewhere, and all was well, for 
the big snake vanished as suddenly as it had appeared, 
obviously bent on escaping being trodden upon. 

Puff adders, being very sluggish, will not get out of 
the way until forced to do so. I have literally pushed 



188 REPTILES AND FISH 

one off the track with a stick because it would not move ; 
a lovely species, the glossy skin marked with carpet 
pattern of different shades of purplish greys and 
pinks, soft browns and creams, harmonizing exquisitely 
with the lights and shades among the dead leaves 
surrounding it. 

This was Bitis nasicornis, the puff adder of forests, 
with a little horn on each side of the nose formed by 
clusters of upright scales. Beautiful as is its colouring, 
the shape is so thick and squat that this species loses 
considerably in beauty from this cause. The much less 
ornamental Bitis arietans, well known in South Africa, 
was once found on Damba Island by my canoe-men 
hidden among the rocks at the very place where the 
canoe was kept. Somehow they managed to get a rope 
round it, and dragged it up in triumph to my house. 
It was 4 feet 6 inches long, and one could not but be 
glad to be rid of so dangerous a neighbour for the bare- 
footed men. 

Mention has been made of the booming noise uttered 
by the crowned crane during the wet season. My boys, 
when asked what made the noise, always replied, " E'sa- 
lambwa " (puff adder). Some puffing ! 

The python is another fine snake, handsomely marked, 
and when in good condition his glossy skin is really beauti- 
ful. I only met with him once, on Kimmi Isle, when I 
came upon a small specimen about six feet long lying 
on a marshy bit of shore. I watched him for some time, 
noting two Glossina fly up from him, one obviously full 
of blood. After a while he became aware of me, and 
moved slowly away, absolutely silently, with the dignity 
befitting a king of snakes. 

On Ngamba Island a place was found where the dead 
leaves in a circular area were flattened, and there was a 
trail of flattened leaves leading to and from it. The 
natives said this was the resting place of an " E'timba " 



SNAKES 189 

(python), which was probably the one previously seen 
on Kimmi, for they swim well, as do most snakes. 

One day when going round Tavu Isle in the canoe 
preparatory to landing, I happened to look over the side 
and saw a snake swimming very gracefully, with the 
top of its head just above water. It soon took fright, 
dived, and was lost to sight in the deep water. It appeared 
to be a young python about two feet long. 

Another snake which on account of its beauty particularly 
calls for mention is a harmless, slender, grass green species 
often seen on the lake shore hunting for frogs, whose 
pitiful cry when once heard is always recognizable again. 
The brilliant grass green colouration and very graceful 
movements of this snake always evoked one's admiration. 

A similar bright green species might sometimes be seen, 
high up among the branches of trees, sometimes travelling 
rapidly and almost leaping across gaps too big to be 
spanned. The manner in which it seemed to spring 
across from one tree to another is very interesting, seeing 
that in the Malay Archipelago certain snakes have carried 
the process further, and take gliding flights from a high 
to a lower branch.^ 

The last snake to be mentioned is a very curious 
and interesting species, which was once found deeply 
buried in the base of a termite hill which was being 
demolished. It was about twelve inches long, greenish 
grey in colour, very smooth, and could move back- 
wards or forwards equally well. The eyeless head was 
so small that the slightly swollen posterior extremity, 
ending in a blunt spike, was larger. When handled the 
snake pressed this blunt spike forcibly against one's hand ; 
doubtless an ignorant person would have dropped it, 
thinking it was biting or " stinging." These snakes are 
entirely subterranean, and are found both in Asia and 
Africa ; presumably they live on worms and burrowing 
^ Shelford, A Naturalist in Borneo, pp. 79-82. 



190 REPTILES AND FISH 

insects, possibly on termites also. This specimen much 
resembled one of the legless lizards found under stones 
or logs of wood, which the Baganda call " Namugoya," 
and the English " blind worm " or " slow worm," in spite 
of their bright eyes and often quite active movements. 
The " Namugoya " is, of course, regarded by the natives 
as a snake, and therefore on no account to be touched. 

Frogs and Toads. 

Frogs have already been mentioned as contributing to 
the sounds heard on the islands. The species most often 
seen on the shore much resembles the European " Green 
tree frog," and may be found freely exposed to the sun 
on leaves or branches. It adapts its colouration to the 
intensity of the illumination, and in very light surroundings 
becomes very light golden green or even milk white. 
Among dark surroundings it is greenish black, but does 
not assume brown tints. Another tree frog, very much 
smaller, seems to be responsible for the shrill tinkling 
noise, like sleigh bells, always heard among reeds and 
rushes after sunset. The green frogs are devoured by 
the green grass snake previously described, and their cry, 
when caught, is pitiful, and surprisingly like that of a 
child. 

Another species — possibly a toad — which is also much 
to the liking of snakes is larger, and has a rough brown 
skin ; it lives by day in burrows which it digs where the 
soil is suitably light. A green snake was seen one day 
with its head down one of these burrows attempting to 
swallow the occupant, and as the mouth of the burrow 
was large and the snake thin, I was able to look past 
the snake and see how the toad had distended itself with 
air to such an extent that the snake, with mouth wide 
agape, could not get a grip on the spherical surface. 
Though it persevered for an hour, with jaws so widely 
apart that upper and lower jaws were almost in a straight 




A SMALL " ENSWA-SWA." 




A VERY ABUNDANT TREE FROG. 



To I ace p. 190. 



SNAKES AND FROGS 191 

line, it could do no more than merely apply itself to the 
toad's side, and eventually had to give up the attempt 
to swallow such an unmanageable victim ! I got the toad 
out, and save for a few scratches made by the snake's 
teeth it was none the worse, and, having deflated itself, 
crawled away quite calmly as if this were no unusual 
experience ! 

It was interesting to see the toad actually save its life 
by its power of increasing its size, and one wonders why 
the snake had not caught hold of a limb. Had the snake 
been a poisonous species, the prey would have been killed 
by contact with the fangs, and even had it been able 
first to inflate itself, its subsequent death would have 
ensured its return to normal size. 

This brings up a point which had always been a difficulty 
to me until I meditated over this and other observations. 
If the poison has been evolved by slow degrees from the 
ordinary non-poisonous saliva, how could this have been 
brought about ? What use could slightly venomous 
saliva be to a snake ? For a creature thus bitten might 
still be able to go away a long distance and die later, 
where the snake would not find it. A clue was given me 
during active service in German East Africa, where I 
first met with the handsome snake called " Boomslang " 
by the Boers, and was discussing the debated question 
whether or no it is poisonous. One old Boer told me he 
had seen one bite a man's arm, which afterwards swelled 
up dreadfully, although the effects were not serious ; but 
many Boers said it was not poisonous. This snake is 
an " Opisthoglyph," i.e. it has not the long fangs of a 
viperine snake, but some of the back teeth are grooved 
in part of their length, and a fold of mucous membrane 
forms a pouch round the groove to conduct the slightly 
poisonous saliva while the snake mouths its prey, for it 
does not strike and let go. Now it is easy to see what an 
advantage it would be to a snake if, whilst it was hold- 



192 REPTILES AND FISH 

ing on to struggling prey, the latter should be weakened, 
even only a little, by injection of slightly poisonous saliva, 
for the prey would then be more easily swallowed. Having 
started thus one can see how the poisonous quality could 
be developed. For the more quickly the struggling 
animal succumbed, the less time would the snake need 
to hold on to it, and the less chance would there be of 
its escaping, until, with the increasing strength of the 
venom, a stage would be reached when the snake would 
only need to strike once, and quietly wait a few minutes 
until the prey, at once seriously poisoned, falls helpless 
and dies. 

An extremely interesting observation is here quoted 
from a letter in Nature by Professor Poulton, dated 
January 2, 1918. Professor Poulton quotes the observation 
for another purpose, but it is so exactly illustrative of my 
point that it is here repeated. Dr. G. A. K. Marshall 
says : " When happening to look over a low stone wall 
near Estcourt, Natal, in 1897, I chanced to observe a 
small snake in the very act of striking a frog. After being 
bitten the latter hopped of! at a great pace, and I was 
rather siirprised to see that the snake made no attempt 
at pursuit, but merely followed in a very leisurely manner " 
(the italics are mine). " Seeing that the frog had come to 
a standstill at a considerable distance ofif, I crept along 
under the wall so as not to disturb the snake, and on 
getting near the frog I looked cautiously over the wall 
to see the end of the tragedy. The snake was still 
some way behind, approaching steadily, and on reaching 
its victim stood watching it for some moments with 
its head raised, the frog meanwhile sitting trembling 
in front of it. At last the snake seized its prey and suc- 
ceeded in swalowing it after hut feeble resistance. It 
seemed clear that the trembling and inability to escape 
on the part of the frog were simply due to the action of 
the poison injected at the first bite." 



>V:">. ; W 










,Ji 



0\E OF THE FLY BOYS HOLDING A SMALL " JLA.MBA " (lUXG FISH). 




"SEMUTUNDU." 
Foot-rule to show scale. 




To face p. 192. 



MAIVIBA AND MALE 193 

The only remark I would pass on this most apt observa- 
tion is that we have no statement from Dr. Marshall 
whether the snake really was a poisonous one : it is only 
presumed to be so from the effects of the bite. 

Fish. 

The most noteworthy fish of the lake is the Lung Fish 
(Protopterus), known to the Baganda as '* E'mamba," and 
a favourite article of food with them. It attains a large 
size, up to five feet long, and has a flattened body with 
broad tapering tail, furnished with a wavy fin along both 
dorsal and ventral edges. The Baganda spear the mamba 
in shallow water, but it may frequently be met with in 
deep, open water, coming up to the surface to breathe 
in the same way as does a tadpole. On one occasion 
a mamba appearing just behind the stern of the canoe 
in which I was sitting emitted the used-up air from its 
lungs with such a loud grunt, that I turned round expecting 
to see a hippopotamus ! 

Having taken a new breath, the mamba turns on its 
side and gives a peculiar heave of its flat tail as it dives 
down again, but, being very conspicuous, it is quickly 
perceived by a soaring fish eagle, who stoops to secure it. 

Probably they spawn during the rainy season in shallow 
water, for shortly after the heavy rains the young may 
be found there. I did not find the tough flesh of the 
mamba worth eating, but that of a species of Siluridae, 
called " E'male " by the natives, is as good as any fish 
I know. It is commonly called " Mud-fish " by the 
English, but specimens caught in the open waters around 
the islands had no suspicion of muddiness, and the firm, 
boneless white flesh was most excellent eating. The Male 
has a flat, broad head covered with bony plates (see Fig.), 
and has long barbels round the mouth. The body is 
somewhat cylindrical ; it may measure two feet or a little 
over. 

14 



194 REPTILES AND FISH 

The Baganda are fond of eating a small, very bony 
fish that haunts shallow water ; they call it " E'nkeje," 
and fish for it with rod and line, and then spike a number 
on a sharp stick and dry them in the sun. This fish is 
also much relished by kingfishers ; it may be a species 
of perch. I saw one in shallow water off a sandy shore 
very busily excavating a funnel shaped pit in the sand. 
With great vigour it would push its snout along the bottom 
until its mouth was filled with sand, and then swim a 
little way away and discharge the load. Whether this 
was destined for a spawning place I know not, but the 
fish furiously drove away any too inquisitive neighbours. 

A very curious fish is termed " E'mbegede " by the 
natives. It has a tubular snout turned down at right 
angles, and presumably obtains its food from mud. I 
saw the remains of one on Kimmi that had probably 
been caught by an otter. 

Other fish well known to the natives are the " Semu- 
tundu," a fish with long barbels, smaller than the Male, 
but much the nicest to eat ; a very large Silurid, called 
" Akasonzi " ; a species commonly sold in the market, 
and much eaten by the English population at Entebbe, 
called ** Ensoga," which somewhat resembles the roach ; 
the beautiful but bony " Ekisinja," a barbel of deep olive- 
green colour, usually caught with rod and line in shallow 
water where ambatch grows ; and a small, very beautiful 
silvery species netted in shallow water, called " Omukene " 
— it is about the size of a minnow. 



CHAPTER X 

THE COLOURATION OF INSECTS 

The study of the colouration of insects has been attracting 
more and more attention from evolutionists, whether of 
the Darwinian or Mutationist school, since Bates ^ and 
Fritz Muller 2 in South America, Wallace ^ in the Malay- 
Archipelago, and Trimen 4 in South Africa gave the first 
explanation of the phenomena now known as Mimicry, 
and interpreted by these naturalists on the lines of Dar- 
win's hypothesis. 

In this chapter examples will be given which have 
come within my own experience on the Sesse Islands, 
and an attempt will be made to show how the Darwinian 
explanation is more satisfactory than that of the Muta- 
tionist. 

In 1890 Poulton classified the colours of animals in 
one scheme, embracing Apatetic or " Deceitful " colours ; 
Sematic or " Warning " colours; and Epigamic or " Court- 
ship " colours.^ The first two headings only will be dis- 
cussed. 

Apatetic colours are divided into Cryptic and Pseudo- 

^ " Contributions to an Insect Fauna of the Amazons Valley." H. W. 
Bates, Trans. Linn. Soc, vol. xxiii, 1862, Pt. III. 
* Proc. Ent. Soc. Lond., 1897, p. xx. 

3 " On the Phenomena of Variation and Geographical Distribution 
as illustrated by the Papilionidae of the Malayan Region." A. R. Wallace, 
Trans. Linn. Soc, vol. xxv, Part I, 1865. 

4 Roland Trimen, " On Some Remarkable Mimetic Analogies among 
African Butterflies." Trans. Linn. Soc. xxvi, 1870, Part III, 1869. 

^ The Colours of Animals, 1890. 

195 



196 THE COLOURATION OF INSECTS 

sematic groups. Cryptic colours are divided by Poulton 
into Procryptic and Anticryptic. Procryptic colouring 
conceals its wearer from danger, causing it to resemble 
either the general surroundings or some particular part 
thereof (Special Procrypsis), Instances of the former, 
such as a green grasshopper among grass, or a mottled 
grey-brown weevil on earth, are so numerous and well 
known that no further examples need be mentioned. 

Special procryptic colouring never fails to arouse 
wonder from its extreme perfection ; indeed, it has been 
said that these resemblances are so minutely perfect that 
Natural Selection cannot possibly have produced them. 

This complimentary doctrine has been termed Hypertely. 

Even in the British Isles stick-like caterpillars abound, 
which are quite indistinguishable until they move. Here 
one must urge a point which is often overlooked. Natural 
Selection, in producing special procrypsis, has not only 
altered the shape and colour of the insect, but has pro- 
duced deeply seated changes in the neuro-muscular system. 
A stick-like caterpillar needs to maintain itself motionless 
for hours in an attitude very unusual for the majority 
of caterpillars, and one which must require great develop- 
men of muscle for that special purpose. 

As an example of another attitude, very unusual, but 
associated with an especial scheme of colouring, the 
following is of interest. 

In 1910 I found at Jinja, on the north shore of Lake 
Victoria, a moth,^ allied to our English Lucania, among 
some very dry dependent spikes of grass flowers, of a 
light silvery grey tint. The moth was hanging in an 
inverted position with wings brought together over the 
back ; their under surfaces thus exposed were of a silvery 
grey hue closely corresponding with that of the dried 
glumes of grass. But this colour was only shown on those 
surfaces that were visible ; the part of the fore wing 

' A species of Cirphis. 




FULL FED CATERPILLAR OF THE NYMPHALINE BUTTERFLY ATERICA GALEKE 

HANGING FROM THE TIP OF A FERN FROND JUST BEFORE PUPATION. 

Photographed in Dainba Island Forest. 

To face p. 196. 



SPECIAL PROCRYPSIS 197 

concealed by the hind wing was of a more usual dull 
grey-brown colour. The moth when disturbed flew away 
to another similar tuft of grass and adopted the same 
attitude again, which was most certainly procryptic, and 
very unusual in a moth of this group, the members of which 
usually rest with the wings brought closely against the 
body. The fact that the silver grey colour was confined 
to those parts of the wings where it was necessary for the 
concealment of the moth by procrypsis is a very important 
point. Many other examples of this nature exist, and are 
arguments against such protective colouration being the 
result of mere chance. Natural selection produces no 
more than is necessary : this is contrary to the doctrine 
of Hypertely. Exactly similar limitations are to be met 
with when studying mimicry. ^ 

Another beautiful instance of special procrypsis is 
afforded by a rare Notodontid moth,^ of which I found 
a specimen at rest on a bush on Damba Isle. The only 
specimen known up till then was the type in the British 
Museum. 

This moth so closely resembled the tube formed by a 
dead,, dry, rolled-up leaf, that I was for long in doubt 
as to its nature, and finally had to pluck the twig on 
which it sat and examine the object most minutely before 
I could decide. 

The wings were closely folded round the body ; the 
inner margins of the fore wings meeting over the back 
were of slightly darker tint than the rest of tjie wing, 
so as to resemble the thick midrib of a dried leaf, whose 
petiole was represented by a curved tuft of long hairs 
projecting upwards from the top of the head. 

The colour of the wings was the shining brown of a 
crisp, dry leaf, and on each side there were several lines 
representing venules, and three doubly ringed markings 

* Essays on Evolution, Poulton, p. 240. 
^ Scalmicauda niveiplaga. 



198 THE COLOURATION OF INSECTS 

like fungus spots. Near the tip was an absolutely pure 
white marking, shining, which probably represented a 
silvery patch such as is often seen on a dried leaf. The 
most realistic portion of the resemblance was the deception 
produced by the very dark brown of the anterior surface of 
the head, which appeared to be the dark shadow of the 
interior of the tube formed by the supposed dead and 
rolled-up dry leaf. 

The completeness of the likeness cannot be realized 
when the moth is seen set in the cabinet, but it was one 
of the most perfect examples of special procrypsis that I 
have ever seen. 

Precisely the same attitude is made use of by the " Bufif- 
tip moth," but in this case the colouring causes it to 
resemble a short piece of very dry stick with light grey 
bark, broken o£E square at one end and obliquely at the 
other. In the case of this moth there is again to be noted 
the profound change necessary for the complete success 
of the deceptive resemblance. The deeply rooted instinct 
to escape when alarmed has been modified into a stronger 
instinct to remain motionless at all costs in order to 
maintain the appearance of a dead leaf, for the slightest 
movement would attract the eye of an enemy, who would 
certainly investigate the object more closely and perhaps 
handle it roughly. The Mutationist who believes that this 
deceptive appearance, so minutely perfect, was produced 
more or less complete in one step, will have to admit 
that the sudden modification of instinct, by a strange 
coincidence, took place at the same time, or that at least 
it occurred in connection with the other. The Darwinian, 
on the other hand, believes that both modifications took 
place by equally slow gradations. 

Very interesting examples of special procryptic colour- 
ation are the resemblances of insects to bird droppings 
on leaves. There is a beautiful example in England — 
the little moth Cilix glaucata at rest fully exposed on a 




< M 



b z 




H V 



o P 



RESEMBLANCE TO BIRD DROPPINGS 199 

leaf.^ The resemblance may be either to a dropping 
which, fallen from a height, has spread out to form a white 
and mottled grey patch on a leaf, or to one which has 
kept its cylindrical shape, and appears dark grey or 
grey-brown and white. 

The young caterpillars of Papilio dardanus much 
resemble the latter object, and their very sluggish habits 
contribute considerably towards the illusion. 

The former class is well exemplified by a beautiful 
Geometrid moth ^ which rests with outspread wings fully 
exposed on the surface of a leaf. The wings are of a chalky 
white hue, with wavy darker lines, and in the centre of 
the fore wing is a dark, irregular patch of black and brown, 
glistening here and there with silver. The whole produces 
an effective likeness, which must be seen in its natural 
surroundings to be believed. If the moth is frightened 
it flies away, but takes up the same exposed position on 
another leaf. 

A propos the silver marking, it is curious how rare 
silver is on insects ; gold is perhaps commoner. Besides 
the above case, the under surfaces of Fritillary and 
some other butterflies, and the marks on some Plusia 
moths, I have only seen one other insect with silver — a 
large Saturnid caterpillar, green, with humps on the 
back covered on one side with pure silver. The attempt 
to rear this beautiful caterpillar was unsuccessful, so the 
name cannot be given. 

Certain insects which resemble bark, and are to be 
found on tree trunks, are very wonderful examples of 
procrypsis, though whether it is special or general pro- 
crypsis is a matter of words only. 

Many Lasiocampidae have caterpillars which are seen 
with difficulty when at rest, so closely do they lie against 

1 First recorded by Sidgwick in the Journal of the Rugby School Natural 
History Society. 

^ Problepsis cegretta. 



200 THE COLOURATION OF INSECTS 

the bark which they resemble. On Damba Isle one of 
my natives came to tell me he had found some caterpillars 
on a tree trunk, and when I went to look he showed me 
three Lasiocampids, lying flat on the bark at a point 
where its surface was somewhat irregular. While looking 
at them and marvelling at the minute detail of the resem- 
blance, I gradually became aware that the immediate 
surroundings of these caterpillars were not bark but more 
caterpillars, and much to the native's amazement, nine 
of them were found lying closely packed side by side, and 
utterly indistinguishable from the bark except by the 
very closest inspection. These caterpillars fed at night 
only,^ crawling up the trunk when the sun set and 
returning to the same resting place next day. The 
perfection of the concealment owes something to attitude. 
The claspers are spread out sideways, so that the body 
lies flat against the bark. The surface of the skin is 
roughened by numerous little excrescences, and the gap 
between the edge of the body and the bark is partly 
obliterated by fleshy lappets, and often by short, 
soft hairs. 2 

It is worth pointing out that a very large insect may 
be concealed in a way that c nnot be believed, unless 
it is actually seen in its natural surroundings. It is well 
known that the caterpillar of the Privet Hawk Moth, 
with its lilac and white oblique stripes, is not so conspicuous 

^ A colony of Eupterotidae caterpillars (Chrysopsyche varia) was found 
on Bugalla Islo resting by day on a tree trunk. Wishing to obtain the 
perfect moth I took some of the caterpillars and kept them in a large 
circular glass topped box in which they rested quietly during the day. 
.When evening came they formed the usual procession and atten>pted 
to climb upwards, which of course they could not do. The result was 
extremely absurd, for the caterpillars formed an endless chain, nose to 
tail one behind another, which ceaselessly promenaded around the cir- 
cumference of the box in the endeavour to find a path upwards. Although 
there was plenty of food in the box they would not eat, since the proper 
preliminary of marching t/jo the tree trunk had not been performed, and 
I had to put the caterpillars back on the tree and hope to secure the 
cocoons later. The limitations of instinct are here well shown. 

* See diagram in The Colours of Animals, p. 30. 



CONCEALMENT OF A LARGE INSECT 201 

as would be expected among the leaves and varying lights 
on a bush, ^ but the following is a more remarkable example. 
On Kimmi Islet I was looking at a bush thinly covered 
with small leaves, and thought I saw a small brown 
" micro " moth sitting on one of the leaves. But gradually 
it became obvious that what I was looking at was not a 
small moth, but part of the ventral aspect of an enormous 
green Saturnid caterpillar, which was on the lower surface 
of a twig, its anterior segments being at an angle with 
the twig, as in the common attitude of many large cater- 
pillars, such as those of our English hawk-moths. The 
closely folded brown legs on the first three segments had 
made the brown area which, against the green of the rest 
of the caterpillar, had been mistaken for a small moth 
sitting on a leaf. There was a whitish-green stripe running 
along the mid-ventral line of the caterpillar, which must 
have served to break up the otherwise uniform green 
area, and helped to render the huge form difficult to be 
seen. The curious point was that when the insect had 
once been visualized, I could not un-see it again, and found 
great difficulty in realizing how I had at first failed to 
discern it. Some of the natives were called up and asked 
if they saw anything on the bush, and their surprise was 
as great as mine when I pointed out the caterpillar. The 
moth was reared, and proved to be Bunaea phaedusa. 

When procryptic colouring is dealt with, place must 
be found for mention of Seasonal Variation. Certain 
butterflies have been known for some years to have 
appearances differing greatly in the wet and dry seasons. 
So marked are the differences in the Nymphaline genus 
Precis, for example, that two forms of P. sesamus, one 
salmon-pink above, the other deep blue, with extreme 
difference of pattern and colour on the under surfaces, 
were thought to be distinct species until G. A. K. Marshall 
bred one from eggs laid by the other. ^ 

^ The Colours of Animals, p. 42. 

' Trans. Ent. Sac, 1902, part iii, p. 414 et seq. 



202 THE COLOURATION OF INSECTS 

Poulton, from careful study of this genus, concluded 
that " dry " forms are more procryptic, and that this 
is due to the operation of Natural Selection during the 
greater stress of the dry season, when insects are so scarce 
that insectivorous animals need to work harder to obtain 
food, and the risk to any particular insect is proportionately 
greater.! Now the climate of the islands of Lake Victoria 
has been shown to be more uniform than that of the main- 
land, ^ and it is very interesting and significant that in 
the case of the commonest Precis there (P. archesia), the 
only form met with was the " wet " one ; and of P. sesamus, 
the salmon-pink " wet " form was so much the commonest 
that the appearance of a " dry " one was quite a memorable 
event. During the campaign in German East Africa, I 
first became familiar with the phenomena of a typical 
dry season, and was soon impressed by the much greater 
procrypsis of the " dry " Precis, and also of such Pierines 
as Teracolus, Belenois, Pinacopteryx. When the grass is 
quite dead and dried up it becomes brown, tinted with 
pink or grey, and the dry season Pierines, when at rest, 
harmonize most admirably with their surroundings on 
account of the suffusion of the under surface with brown, 
grey or pinkish scales, so that they are often exceedingly 
difficult to detect after they have alighted. It is note- 
worthy that, just as in the case of the moth above men- 
tioned, this especially procryptic colouring is only found 
wher*^ it is needed on the under surface, viz. on the whole 
-of the hind wing, but only on the tip of the fore wing, 
which is not covered by the hind wing in the position 
of complete rest. The remainder of the under surface 
of the fore wing is as in the " wet " form. 

The above examples of conceaUng colouration are all 
procryptic ; that is to say, they are species, found highly 
desirable by vertebrate enemies, which have acquired 

1 Trans. Ent. Soc, 1902, part iii, pp. 424-443. 

2 See chart. Chapter iii. 



ANTICRYPSIS 208 

colours, shape and habits concealing them from dis- 
covery by enemies. 

The class of anticryptic colouration has not so many 
examples. In it are to be found creatures whose con- 
cealment aids them, primarily, not to escape their enemies 
but to obtain their prey. 

On many occasions I have seen a butterfly apparently 
caught by a flower which it had visited, and at first imagined 
that the proboscis had become entangled. On examining 
the flower it was found that the butterfly had been caught 
by a spider, which had lain in wait on a flower which it 
so closely resembled that, until one had had this experience 
several times, one still imagined it was part of the flower. 

Two species, or possibly two forms of the same species, 
have been frequently met with that thus caught their 
prey, both of the " crab-spider " type. One was found 
on a yellow flower like a small sunflower, the other was 
on a milk-white flower of a small low-growing herb. In 
each case the spider was of precisely the same tint as the 
flower on which it caught its prey. 

The curious and interesting Mantidae are often quoted 
as instances of anticrypsis. A species Pseudocreobotra 
ocellata was abundant on the islands, and, like the spider, 
varied in hue according to the colour of the flowers which 
it frequented in order to catch its prey. One form, green 
and yellow, was found on the small " sunflower," the other, 
green and mauve, sat among the spikes of purple flowers 
of an abundant aromatic labiate herb. Very young speci- 
mens found on the latter were of a uniform purple or 
mauve tint, and it was extremely difficult to see them. 

In aU these cases, however, the ^rocryptic element 
cannot be definitely set aside, since birds are well known 
to eat spiders, and Mantidae are so universally cryptic 
that they must be supposed to be highly edible. ^ 

1 In 1916-17 I had a tame Cercopithecus monkey which, taken out 
to himt for itself, would devour Mantidae with the utmost avidity. 



204 THE COLOURATION OF INSECTS 

But the foUomng example i.s more probably anticryptic. 

On Nsadzi Isle there is a fine sandy beach frequented 
by Egyptian geese and wading birds, whose droppings 
attract little blue butterflies and Skippers, which settle 
on them to feed. I found one day, sitting on a patch 
of bird dropjDing and sucking the juices of a captured 
Lycaenid butterfly, a small flat bug, Mononyx grandicollis, 
of the group Cryptocerata, whose tints accorded admirably 
with those of the dropping on the wet sand. 

Hitherto we have been considering examples of insects 
concealed by their resemblance to their surroundings. 
But a large number of species are extremely conspicuous, 
and many of them seem to court attention, I use these 
words dehberately, and as a result of several years' obser- 
vation in the field. But a school has arisen in America 
following the teaching of the distinguished artist-naturaHst 
Thayer,! which believes that all creatures are concealed 
by their resemblance to their surroundings, no matter 
how brilliant and startling their colouration appears to 
be in the cabinet. Many butterflies are supposed to be 
like the flowery part of their surroundings. ^ In some 
cases this is certainly true ; the greenish-yellow Pierines 
of genus Terias, when feeding from yellow flowers among 
herbage, are very well in harmony with them, and quite 
well concealed. So also the under surfaces of the wings 
of other Pierines tone very well mth flowers or grasses ; 
our own orange-tip is a well known instance. 

But these are all what a Darwinian calls procryptic, 
so that here there is no difference between him and the 
follower of Thayer. When the species which Poulton 
called Aposematic (i.e. with " warning " colouration) are 
considered, it is difficult to accept the doctrine that they 
really harmonize with their environment or with any part 
of it. Take for example the typical habitat on the islands 

* See Concealing Coloration in the A7%imal Kingdom. 
2 Loc. cit., pp. 228-229. New edition, 1918. 



THAYER'S VIEWS 205 

of a typically aposematic butterfly, Acraea egina. This 
brilliant black and scaiMet species could be seen in great 
numbers on the open grass land near the well defined border 
of the dense forest which, as has been described, ends 
abruptly, presenting a dense wall of greenery among ' 
which one searches in vain for scarlet flowers or any patch 
of scarlet with which the Acraea could harmonize. Near 
the edge of the forest, but often as much as a hundred 
yards away, in the open grass land, flourish clumps of 
the plant Erlangea tomentosa, which bears fine heads 
of lavender coloured flowers. These are extraordinarily 
attractive to Acrasines, which crowd together on them, 
making a brilliant picture. Not only the black and 
scarlet Acraea, such as egina, zetes, perenna and the 
rarer pJiarsalus, together with smaller species similarly 
coloured, but black and white females of Planema macarista, 
P. alcinoe and P. aganice, the brown males of the two 
latter, and black, orange and white males of P. macarista, 
with both sexes of the similarly coloured P. poggei, all 
congregate in various proportions, and being freely exposed 
on the lavender heads of flower, make a very brilliant 
and conspicuous assembly which by no stretch of imagin- 
ation could be considered to harmonize with the surround- 
ings. 

It is true that one tree with brilliant scarlet flowers, 
known to the Baganda as " Ekirikiti " {Erytkrina tomentosa), 
is plentiful on the islands, but butterflies do not visit 
it, and it usually has no leaves at the time of its flowering, 
so that the isolated bunches of flowers high up in the air 
can hardly be considered to form a background against 
which scarlet butterflies would be invisible. Moreover, 
the tree usually stands by itself in open places. 

It must, I think, be admitted that such insects as the 
above are conspicuous in their natural surroundings, and 
the explanation, first suggested by Bates, is that these 
are relatively distasteful species, to whose advantage it 



206 THE COLOURATION OF INSECTS 

is that they should be as conspicuous as possible in order 
that their vertebrate enemies may readily recognize them 
as things to be avoided. The colours of such creatures 
are therefore known, in the terminology used by Poulton,^ 
as " warning colours " or " aposemes." 

Obviously it will be to the advantage of such insects 
that their aposemes should be of simple type to aid recog- 
nition and memory on the part of the enemy. Hence 
one finds schemes such as black and yellow alternating 
rings in a wasp, or, in a butterfly, the wings of one colour 
except for strongly contrasted patches of another colour, 
especially at the apex of the fore wing. It is an interesting 
point that this apical or sub -apical patch of contrasting 
colour usually has its long axis at right angles to the long 
axis of the wing. Presumably the transverse direction 
makes the patch more conspicuous during the movements 
of the wing than if it were parallel to the long axis of the 
wing. This point is well shown in the illustrations of 
the various Planema (see Plates). 

Before dealing with typically aposematic species, it 
may be said that quite a number of procryptic insects 
are furnished with an aposeme which they display if 
an inquiring enemy comes unpleasantly near. The 
caterpillars of Lasiocampidae, previously alluded to, 
show, if disturbed, a cleft across the second or third 
segments, or both, filled with brightly coloured fine 
sharp spines, which very readily become detached 
and penetrate one's skin, and would prove very un- 
pleasant in the mouth of an enemy tasting such a 
caterpillar for the first time. The colour of the spines 
varies in different species. It may be orange, or pink, 
or steely blue-black, but is always such as to make the 
spines very conspicuous. When the caterpillar is quietly 
at rest and concealed by its procrypsis, the cleft is closed, 
but if the caterpillar is disturbed or touched it makes 

1 The Colours of Animals, pp. 336-337. 




BLACK AND WHITE AI'OSEMATIC CATERPILLARS OF THE LARGE NOCTUIU 
MOTH AMBLYPRORA MAGNIFICA. 



PROCRYPSIS COMBINED WITH AN APOSEME 207 

the cleft gape widely open, so that the brightly coloured 
spines are fully displayed. This may be seen in England 
in the caterpillar of the " Lappet " moth. 

In the case of these caterpillars it must be remembered 
that the presence of such an aposeme does not necessarily 
imply that the caterpillar is intrinsically distasteful, but 
that it possesses some unpleasant quality on account of 
which it had better be left alone. I have a certain amount 
of evidence that Hymenoptera, such as the stinging ants, 
bees and wasps, are not avoided so much on account of 
inedibility as on account of their powers of defence, which 
they advertise by their conspicuous scheme of colouring, 
or their habits. 

So that the combination of procrypsis with an aposeme 
is not so inconsistent with the theory of natural selection 
as it might appear to be at first. Another interesting 
example of this combination is a fine large Noctuid moth, 
abundant on the islands (Ophideres). It was usually first 
seen on the wing after it had been disturbed from its 
resting place, when its orange hind wings bordered with 
black were very conspicuous. If it was followed up it 
was seen to settle head downwards on the bark of a tree, 
expose fully for a moment its orange hind wings, and then 
suddenly close the wings with a snap and become invisible 
owing to the mottled grey-green and brown tints of the 
fore wings closely resembling the surface of the bark. 
I am inclined to think that the conspicuous hind wings 
are aposematic, else why should the moth take such pains 
to display them for a moment, on alighting, before covering 
them with the procryptic fore wings ? I suggest that the 
moth endeavours to dissuade a pursuing enemy by freely 
displaying its warning colours, and then settles and be- 
comes invisible to any new enemy that had not seen it 
when on the wing. 

On the other hand, it is possible that the colour of the 
hind wings is of the nature of directive markings,^ which 
* Colours of Anhnals, p. 204 et seq. 



208 THE COLOURATION OF INSECTS 

entice the enemy to seize an insect at some particular 
part which is especially brittle, and, being seized, breaks 
away, so that the insect escapes unharmed save for the 
wholly immaterial loss of some part of the wing. Such 
special directive marks often take the form of conspicuous 
eye-like spots at the angle of the hind wing or along its 
margin, or of tails, and every collector must have noticed 
how often in Papilio, Charaxes, Satyrinae, Lycaenidae such 
parts are missing, and a gap in the margin of the hind 
wing shows where the enemy has secured nothing but a 
mouthful of dry wing tissue. These gaps in the wing 
are just in the position where the wings are least likely 
to be damaged by contact with objects during flight. 
Moreover, it is just these pieces of the wing which break 
off when the butterfly is vigorously fluttering in the folds 
of a net ; the tails of Papilionidae are notorious in this 
respect. 

On one minute islet that I visited there were numbers 
of black and white wagtails, and little Lycaenid butterflies 
were plentiful. It was noticed that a large proportion 
had a A-shaped piece missing from both hind wings 
symmetrically as if a wagtail had seized the butterfly 
by the hind wings when it was at rest, and the butterfly 
had escaped owing to that portion of the wing breaking 
away. After leaving the islands in 1915 I was fortunate 
enough to see this actually happen, and also to see 
numbers of Lycaenidae actually eaten by wagtails.^ The 
question of directive markings has been here dealt with 
because it seems possible that certain instances of very 
simple, conspicuous patches of colour, which in the dead 
specimen look like aposemes, are possibly directive mark- 
ings, I refer especially to the orange, crimson, or purple 
tips of the fore wings of the Pierine genus Teracolus. 
These lovely butterflies are conspicuous on the wing, but 
shy and wary. When one is fluttering in the net the 

1 Vide p. 238 



BEHAVIOUR OF APOSEMATIC SPECIES 209 

orange tips very frequently are broken, which is an un- 
usual occurrence with butterflies, the anterior part of the 
wing usually being the strongest (c/. supra). As has 
been said, the lower surfaces of these butterflies are de- 
cidedly procryptic, but it must be acknowledged that, 
as in our English " orange-tip," the bright colours of 
the Teracolus are more developed in the male, so that 
sexual selection may have been a factor in producing 
them {vide infra). 

We must return to the subject of aposemes, having 
digressed somewhat. 

Just as cryptic insects must behave in accordance with 
the resemblance to their surroundings, so aposematic 
species have a behaviour in keeping with their colouring. 
It would be of Uttle use for a gaudy, distasteful insect 
to retreat timidly or endeavour to hide itself on approach 
of an enemy which, only partially seeing it, might grab 
at it and damage it fatally before the mistake was found 
out. Everything is to be gained by flaunting the banner 
in the face of the enemy, so that there can be no possibility 
of a mistake. Consequently, aposematic insects are of the 
boldest demeanour, and are the species most frequently 
seen by the casual observer. If endeavours are made 
to catch one, for instance a Planema butterfly, it merely 
flits out of reach, and returns to the same spot apparently 
unalarmed. 

A large grasshopper {Dictyophora laticincta), of family 
Acrididae, was frequently met with on the islands fully 
exposed on pathways : a bloated creature with heavy 
body, whose wings are so atrophied that it cannot possibly 
fly. So sluggish is it that it scarcely troubles to move 
out of the way, or gives a feeble hop merely carrying it 
for a distance about equal to the length of its own body. 
In colour it is grey-black, and the short wings are scarlet, 
and there is some of the same colour along the sides of 
the fat abdomen. If persistently annoyed it will raise 

15 



210 THE COLOURATION OF INSECTS 

the wing covers to show the red wings underneath. Such 
an insect, a priori, must be distasteful, and proved to be 
so when offered to my young monkey, who would eat 
greedily until he was sick equally large, but procryptic, 
grasshoppers. 

Since I offered this grasshopper to Wee Man he naturally 
thought it would be edible, and at once seized it, though 
he did not straightway bite it as he would have done 
had it been the ordinary procryptic species he was accus- 
tomed to eat. While he held.it in his hand the grasshopper 
emitted copious bubbles of strongly smelling yellow froth 
from the thoracic spiracles, forcing it out by first dis- 
tending and then strongly contracting the abdomen, so 
that a hissing sound was produced, audible several yards 
away. At the same time the wing covers were raised 
so as to display the bright red, black bordered wings. 

Wee Man was obviously much interested in this very 
curious and, to him, novel phenomenon, and tasted the 
froth, but though he obviously did not like it, he persisted 
in trying to eat the insect, pulling it to pieces and tasting 
each. But none of it was actually eaten ! 

Many other insects, none of which are procryptic, emit 
strongly smelling, bright coloured fluid when roughly 
handled. This is well known to all who have collected 
Acraeine butterflies. 

The following is quoted from my article in Bedrock ^ : 

*' A most typically aposematic Arctiid moth {Bhodo- 
gastria leucoptera) was found resting fully exposed on low 
herbage. Its wings were of a pure hard shining white, 
but not very thickly scaled, so that when they were brought 
together over the body of the moth, the abdomen, which 
was of a bright rose pink, was distinctly visible. The 
thorax was pure white, spotted with black. The legs 
were of the same bright rose as the abdomen. When 
the moth was disturbed it separated its wings and spread 

' Vol. ii, 1913, "Notes on the Struggle for Existence in Tropical Africa." 



BEHAVIOUR OY APOSEMATIC SPECIES 211 

out the legs so as to display the bright pink (a typical 
aposeme), and emitted from the thorax just behind the 
head a copious yellow froth, till a mass of yellow bubbles, 
with a very strong acrid odour and taste, projected on 
each side." 

Equally remarkable is another specialized grasshopper, 
known to the Baganda as " Semukutu." ^ It is a large 
heavy insect of dull greenish-grey colour, and though 
not in any way aposematic in colouration, yet has all 
the characteristics of such an insect. It has no trace 
of wings or wing covers, and the thorax is set with spines 
around its margin. The abdomen is fat and bloated, 
and the sluggish insect makes no attempt to evade an 
approaching enemy. I could never induce a monkey to 
tackle one of them. When handled, a Semukutu ejects 
with some force from the sides of the thorax a yellow 
fluid of strongly acrid odour, which would prove extremely 
unpleasant in the mouth ; and, indeed, the Baganda will 
not even handle the insect, for they say the fluid produces 
sores on the skin.^ But I never found that it had any 
effect on my skin, and I have handled a great many 
Semukutu. This is an interesting case, for here we have 
an insect which has acquired the habits and attributes 
of an aposematic species, yet not the colouration. Indeed, 
a young specimen is rather procryptic, being mottled with 
green, but it has not then the power of exuding the 
acrid fluid. One might, however, suggest that the appear- 
ance of this stout, spiny, wingless grasshopper is so unlike 
that of others that it can be very easily recognized, and 
the need for aposematic colours may not have arisen. 

The above observations on the monkey and grasshoppers 
have exemplified the deliberate use of an aposeme by an 
insect when hard pressed. This is again brought out 
very well by an experiment with fowls, the subject being 

^ Enyaliopsis, possibly durandi. 

* See Bulletin of the Entomological Research Committee, vol. i, p. 227, 



212 THE COLOURATION OF INSECTS 

Phymateus viridipes, another large grasshopper of a hard 
green colour, with spiny thorax, and fully developed blue 
and crimson wings, so that when flying it is extremely 
conspicuous. 

One of these was put on the ground some little distance 
away rom a group of fowls, one of which at once ran 
up to it. The grasshopper remained where it was, but, 
when the fowl came dangerously near, raised the wings 
and wing covers perpendicularly and opened out the 
former to show their bright red colouring. The fowl 
halted, looked at it, turned round and walked away, 
nor could it be induced to touch the insect. After a 
similar result had been obtained on another occasion, 
the grasshopper was killed and laid down near the fowls, 
.^ho wings being of course hidden beneath the covers. 
A half-grown fowl at once ran up and pecked at it, and, 
being pursued by another, ran off with the grasshopper, 
put it down and pecked at it again, but certainly did 
not seem to relish it, finding it very tough. The fowl at 
length picked off the legs, but made no impression on the 
body. 

Just as it was about to leave it, a second half-grown 
fowl rushed up, took it away and pecked vigorously at 
it, pulled off the head but did not eat it, and finally 
walked away and left it. These observations show, 
firstly, the value of the aposeme in warning off dangerous 
enemies, and secondly, the distastefulness of the owner. 

It will have been noted that the fowl made no impression 
on the tough body of the grasshopper, and this brings 
out another point. Should an aposematic insect have 
the misfortune to be one of those that are tasted by an 
inexperienced young foe, it may quite possibly survive 
the tasting, and be able to propagate its kind if it is of 
sufficient toughness. Consequently one finds that apose- 
matic species, in strong contrast to procryptic species, 
are endowed with astonishing powers of resisting injury, 



HAIRY CATERPILLARS 213 

at any rate in the case of Lepidoptera. It is quite impos- 
sible to kill a Danaine or Acraeine butterfly by the mild 
pinch on the thorax sufficient for a non-aposematic Pierine 
or Satyrine, for their tissues are so elastic that but little 
impression is made on them. Further, such insects have 
remarkable powers of resistance to chemical poisons.^ 
It takes a very long time to kill an Acraea, or a Burnet 
moth, in a cyanide bottle, and I have had Planema pupae 
all night in a killing bottle, which when taken out in the 
morning were unharmed, and showed their characteristic 
movements, although that very bottle was in daily use 
for other insects, which very quickly succumbed. 

It has been pointed out above that a disagreeable taste 
or smell is not the only quality associated with aposemes, 
as in the case of the sting of a wasp. The well known 
irritating qualities of fine hairs from Arctiid, Lymantrid, 
or Lasiocampid caterpillars, or the spines of Apodid or 
Saturnid caterpillars are all found to be associated with 
typically aposematic colouration. In this case the aposeme 
has no bearing on the actual taste of the insect, but only 
refers to the presence of some irritant or penetrating 
hairs ; indeed, many such caterpillars, as in Lymantridae, 
become typically procryptic, and presumably edible moths. 
But the rule cannot be stated that when the aposeme is 
due to adventitious hairs, etc., the insect is not distasteful 
in itself, for many Arctiid caterpillars renowned for their 
hairiness, such as the " Woolly Bear," become typically 
aposematic moths, such as our English " Tiger-moth." 
It would, however, be very interesting to test the edibility 
of Lymantrid and Arctiid pupae removed from the hairy 
cocoon. On the other hand, when a caterpillar has 
aposemes that are, as it were, intrinsic, that is, not de- 
pending upon hairs or spines, it seems to be the rule hat 

^ It must be acknowledged, however, that certain very procryptic 
weevils, found on the ground which they closely resemble, have equal 
powers of resistance to chemical poisons, but they are exceptional in 
this respect among procryptic species. 



214 THE COLOURATION OF INSECTS 

its distasteful qualities are carried through all stages 
to the perfect insect. I do not know of a case of an 
aposematic larva of this type becoming a procryptic, 
and therefore edible, adult. A most typical instance is 
the Hypsid moth, pactolicus, which is equally conspicuous 
in all its stages. The caterpillar is ringed alternately 
with dead black and pure Chinese white, the head being 
crimson. It feeds fully exposed on a yellow flowered 
vetch, 1 on which it is visible from far away. When full 
fed it stretches a few silk threads across and across to 
make an open hammock, in which it becomes an equally 
conspicuous chrysalis, fully exposing its light yellow 
colouring with black markings. The large adult moth 
is bright orange with steely blue-black blotches, and is 
one of the most conspicuous insects ; it is of sluggish 
habit, and rests freely exposed on low herbage, or flies 
slowly and heavily. The moths of this family are some- 
times copied by other less favoured insects, and there is 
little doubt that they are relatively distasteful. 

On the other hand, cases of a procryptic caterpillar 
becoming an aposematic adult must, I think, be exceptional. 
I have not yet met with one on the islands. 

A very interesting species is the typically aposematic 
genus Aletis. These moths are sometimes mimicked by 
butterflies (see p. 233). One species, A. erici, was found 
in abundance on Sanga Island in such numbers that the 
bushes had been completely stripped of their leaves 
(see p. 103). The caterpillar was tawny orange with black 
blotches, and was extremely conspicuous ; since many 
grouped themselves together, hanging head downwards in 
clusters from the bare twigs, their attitudes accentuated 
the conspicuous colouring — they had the typical shape 
of all Geometridae. Inasmuch as the vast majority of 
Geometrid larvae are procryptic, the ancestral forms were 
probably so, and the Aletis has been transformed from a 
^ Crotalaria striata. 



APOSEMATIC INSECTS CROWD TOGETHER 215 

procryptic to an aposematic type, the larvae still retaining 
the characteristic shape and the attitude which follows 
from the absence of the first three pairs of claspers, but 
acquiring the habit, most unusual among Geometrid larvae, 
of grouping themselves so that the effect of the warning 
colours is accentuated — a habit not at all uncommon 
among aposematic insects. 

The Peyitatomidae, highly odoriierous Hemiptera, resplend- 
ent in green or blue and gold, commonly mass together. 
In 1917 I met with a very marked instance of this 
aggregation. An Acridian grasshopper, ^ conspicuously 
coloured green, orange and black, and of typically apose- 
matic habits, was proved very definitely to be distasteful 
to a young monkey. When very young it is coal black, 
speckled with yellow, and on several occasions large 
numbers were found closely crowded together to form a 
black mass at the end of a spray of herbage, which attracted 
my attention, whereas a single individual from its small 
size would easily have escaped notice. Some of these 
black youngsters were given to a monkey, who would 
not even taste them, although hungry, as was proved 
by his subsequently eating other insects. Although the 
habit of collecting in a mass, whereby the conspicuousness 
'of an individual is much exaggerated, is most commonly 
made use of for aposematic purposes, yet I have met 
with an instance where a full effect of procrypsis was 
only produced when a number of individuals collected 
together in a certain way. The effect produced was a 
likeness to a bird-dropping on a leaf, and could not so 
well have been produced by a single individual. 

The species concerned is the Bombycid moth, Trilocha 
obliquissima, of which the type specimen, from Angola, 
was the only one in the British Museum collection. A 
company of very young caterpillars was found on Bugalla 
Island on a leaf of a Sapotaceous tree, Chrysophyllum. 

^ Zonocerus elegans. 



216 THE COLOURATION OF INSECTS 

The general colouration was a mottled stony grey. After 
the first moult the lighter parts of the markings became 
chalky white, and as the caterpillars always lay close 
together in a mass, and fed on the flat surface of the 
leaf from the upper parenchyma only, the resemblance 
to a bird dropping was very close. At the next moult 
the caterpillars became darker, and as they grew larger, 
after the third moult, were of a rich brown. They now 
had different habits, feeding from the edge of the leaf 
in the manner of all large caterpillars, and no longer 
massing together. 

When full grown they were extraordinarily procryptic, 
being of the same rich brown as the leaf stalks, with green- 
ish and purpUsh mottlings, the body being swollen here 
and there with numerous scale-like excrescences accurately 
resembling scales at the bases of the leaf stalks, and 
rugosities of the bark. The caudal horn, projecting 
forward over the back, also helped in this likeness. The 
caterpillars now rested along twigs and leaf stalks, and 
adopted a special attitude, which rendered them more 
procryptic. 

An instance has been given of the use of an aposeme 
on certain occasions only. The following is a very re- 
markable instance of a structure useful at one stage of 
development being apparently made use of to protect 
a subsequent stage. 

The larva of the Lasiocampid moth, Chrysopsyche varia, 
is quite conspicuous, being coloured a rich chestnut brown 
with large pale blue spots. When full grown it has in 
addition on the dorsum of each segment from 4-10 
a dense patch of very short, closely set fine hairs of 
glistening white. 

It has been already mentioned as showing peculiar 
limitations of instinct (p. 200). When full fed, it spins a 
firm brown cocoon of the type usual among Lasiocampidae. 
The point of interest is that at one end of the cocoon, 



USE OF LARVAL APOSEME BY PUPA 217 

opposite to the posterior extremity of the occupant, a 
weak spot, ahiiost a hole, is left. When the caterpillar 
becomes a chrysalis the discarded brightly coloured larval 
skin is pushed out so that it partly projects through this 
hole. It is naturally to be expected that the adult moth 
would emerge through this hole, but it does not ; it pushes 
its way out in the usual manner through the other end of 
the cocoon. Now if the object of the weak spot is to 
allow the discarded larval skin to be extruded so as not 
to take up space inside the cocoon, one would expect 
it to be got rid of completely, but this is not the case ; 
it remains partly inside, partly outside, ^ its bright colours 
freely visible. Apparently the pupa makes use of the 
discarded aposematic skin to protect itself. I have not 
met with another case of this partial extrusion of the 
larval skin through an orifice especially provided. 

Insects furnished with well marked aposemes are 
commonly said to be protected by the possession of sting, 
distastefulness, spines, hairs, irritant fluid, exceptional 
hardness, etc. It must be understood that this immunity 
from attacks by birds or mammals is not by any means 
claimed to be absolute at all times, but is entirely relative, 
depending upon the abundance of insect food generally, 
of that species in particular, and the state of hunger of 
the enemy, who, when food is difficult to obtain, will eat 
species which he would pass by when more edible insects 
could be easily found. ^ Also it must be remembered that 
certain creatures appear to be specialized for devouring 
prey which others pass over. 

^ In a certain nnmber of cases the skin is completely extruded — 
evidently the habit, if it is of protective value, has not yet been carried 
to its fullest efficacy. 

2 See Poulton, E. B., The Colours cj Animals, pp. 180, 181. Marshall, 
G. A. K., The Bionomics of South African Insects. Trans. Ent. Soc. 
Lond., 1902, part iii. Swynnerton, C. F. M., Proc. Ent. Soc. Land., 
February 3, 1915; and in "Experiments and Observations bearing on 
the Explanation of Form and Coloviring." Journal Linn. Soc, 1919» 
Zoology, xxxiii. 



218 THE COLOURATION OF INSECTS 

Thus a Roller which was examined at Jinja was found 
to have devoured numbers of a bright green ball-rolling 
dung beetle, a member of a family whose habits render 
them nauseous to monkeys, and which emit a very foul 
smelling fluid when handled. 

Bee-eaters (Merops) feed on bees and other stinging 
HymenopteraP- cuckoos appear to feed largely on very 
hairy caterpillars. Now it is well known that every living 
thing produces very many more offspring than can possibly 
survive, and Wallace pointed out, in 1858,^ that, of the 
offspring of one pair, on the average all but one must die 
or at least fail to produce young. So that any one who 
refuses to accept the explanation that aposematic colours 
and habits are produced by Natural Selection is quite 
justified in saying, " If you claim that these species escape 
being devoured by vertebrate enemies, the burden is laid 
on you of proving by what means they are prevented 
from overrunning the earth." 

In order to answer this, all the restraining factors must 
be considered. 

Firstly, there are the vertebrate enemies, birds and 
beasts, against which it is claimed aposematic insects 
are protected. Secondly, predaceous insects, such as 
dragon flies, carnivorous beetles and bugs, and Asilid 
flies, which eat or suck juices of other insects. Spiders 
are not here included, for they appear to be indiscriminate 
feeders on protected and unprotected alike. For the 
same reason fossorial Hymenoptera, which feed their 
young on other insects, are not here included. Thirdly, 
there are parasitic Hyinenoptera and Diptera, which lay 
their eggs on other insects ; and fourthly, the micro- 
organisms of disease. 

^ See Reports of Sleeping Sickness Commission, vol. xiv, 1913, pp. 15, 
16, and table extracted therefrom in Chap, viii, p. 172. 

* " On the Tendency of Varieties to depart indefinitelj'from the Original 
TjT)e." Essay reprinted in Natural Selection and Tropical Nature, 1895 
edition, pp. 2-i-5. 



ENEMIES OF PROTECTED INSECTS 219 

Let the number of o£fspring of any two parents destroyed 
by each of these agencies be represented, in order as 
above, by V, P (with above described Hmitations), p and 
M : then if X be taken to represent the total number 
of offspring, X — 1 represents the number destroyed by 
all agencies together. So the equation can be written : 

X— l = V+P+i? + M. 

And the number destroyed by any one agent alone 

V = (X-l)-(P + 2? + M). 

It is obvious, therefore, that if, as is claimed, V is negligible 
for protected species, P+2?+M must be correspondingly 
greater, and there is some reason for thinking that this 
is actually the case, although much statistical evidence 
is required. 1 For instance, in the case of P, those who 
have paid attention to, or observed in the field, predaceous 
insects with their prey,^ have probably had the same 
experience as myself, that the prey is very often among 
precisely those species which are believed to escape 
molestation by vertebrate enemies. Thus I found a com- 
pany of spiny black and yellow larvae of Acraea perenna, 
of which many had already been sucked dry by a bug,^ 
which was found in the act of sucking one. This one 
bug might very easily have destroyed seriatim the whole 
of the brood of these aposematic larvae. In the case 
of p we need especially comparative statistics showing 
the relative proportions of aposematic and cryptic species 
that are destroyed by parasites ; the following bears on 
the subject. Acraea zetes, a typically aposematic scarlet 
and black butterfly, abounded on Bagalla Island, and its 

1 See Trans. Ent. Soc. Land., 1902, part iii, pp. 328-38. 
* See collected data by Poulton, Trans. Ent. Soc. Land., 19C6, part iii, 
pp. 323-409. 

^ Damarius splendidulus. 



220 THE COLOURATION OF INSECTS 

larvae, ringed alternately with orange and slate grey, 
with black spines and crimson head, could be found in 
numbers when full fed wandering over the grass land in 
search of suitable places for pupation. Judging by the 
situations in which the pupae were found, the larva chooses 
as conspicuous a site as possible, such as a tall grass stem 
fully exposed and unsheltered, quite out in the open. 
Numbers of these full fed larvae and of the equally con- 
spicuous pupae were collected, and out of seventy, 77 per 
cent, were destroyed by parasitic Diptera (Tachinidae) 
and Hymenoptera {Chalcididae, Braconidae). 

Lastly, in the case of M. The very peculiar and highly 
specialized legless caterpillars of the Apodidae are often 
brilliantly coloured, and furnished with intensely sharp 
strong spines set in clusters, often said to be " poisonous," 
so irritating are their qualities. The Baganda have a 
great dread of these stinging caterpillars, which they 
brought me with the utmost caution. I was very seldom 
able to rear them, for they seemed to be extraordinarily 
susceptible to some disease which very rapidly killed 
them. Possibly it was of the same nature as the 
" pebrine " which Pasteur investigated in silkworms.^ 

A very interesting special case of aposematic colouring 
is the development of " Terrifying " marks, and just as 
with the cases previously described, the colouration is 
associated with a special attitude, whose purpose is to 
make the specialized areas of colouring suggest some- 
thing that frightens or discourages the enemy. In many 
cases the attitude is far more important than the colouring. 
I would refer the reader to Poulton's book,^ and wish here 
merely to describe an example from my own experience. 
The large and handsome moths of the family Saturnidae 
very often, like our " Emperor moth " of the heather 

* Comparative statistics of the number of caterpillars, procrj'ptic and 
aposematic, destroyed by p and M would bo exceedingly valuable. 
' The Colours oj A^iimals, p. 258 et seq. 



TERRIFYING MARKS AND ATTITUDE 221 

moors, have large eye-like markings on the hind wings, 
which are concealed by the fore wings when the moth 
is at rest, but under certain circumstances are exposed. 
One of these, a comparatively dull coloured species, was 
offered to my pet monkeys on Bugalla Island. The 
following account is quoted from my article in Bedrock.^ 

" The moth was a large yellow species with well marked 
eye -like spots on the hind wings. When alarmed it bent 
the body ventrally into a strong curve, and held the wings 
in a very curious and unusual fashion — almost upright, 
with the upper surface directed forwards so that the 
eye-like markings were extremely conspicuous ; indeed, 
the attitude was obviously intended to display those 
* eyes.' The moth thus looked curiously weird and un- 
mothlike, and the monkeys were afraid even to touch it. 
It was not merely the size of which they were afraid, 
because they caught and readily devoured large and 
protectively coloured moths (Sphingomorpha) often found 
about the house." 

Finally, it must not be concluded that all bright colours 
in insects are aposematic. In the case of butterflies both 
surfaces of the wings must be considered ; only the lower 
surface is displayed when the insect is at rest and likely 
to be caught unawares, for when on the wing a butterfly 
is alert and can escape by flight. Consequently a large 
number of species, the upper surfaces of whose wings are 
vividly coloured, are really procryptic if the lower surfaces 
be considered. I need only mention our English " Red 
Admiral," and the famous leaf butterflies of Asia and 
Africa [Kallima). 

Darwin concluded that the colours of butterflies owed 
much to Sexual Selection, and those who have seen butter- 
flies courting will probably agree that vision does enter 
into the question. I have seen a male Bapilio dardanus 

* " Notes on the Struggle for Existence in Tropical Africa," Bedrock, 
1913, vol. ii, p. 366. 



222 THE COLOURATION OF INSECTS 

in headlong flight through the forest suddenly arrest its 
course and dally awhile with' an Amauris niavius, and it 
was impossible to resist the conclusion that the swallow- 
tail had for a moment mistaken the Amauris for its own 
female of the form hippocoon, which closely resembles 
Amauris. Eltringham ^ has described an elaborate appar- 
atus in male Amauris which I was fortunate enough to 
observe being actually used in courtship by A. psyttalea, 
on Bugalla Isle, in July 1912. A male was flying about 
after a female, which presently alighted on a dead flower 
spike of a common herb about two feet high. She sat 
almost at the top, vertical, with head upwards and wings 
outspread, and remained perfectly still while the male 
hovered a few inches above her head with a peculiar 
flutter causing him to rise and fall a little. Every now 
and then the flaps at the extremity of the body were widely 
everted at right angles to the body, and a large white 
brush-like structure was most energetically protruded and 
as rapidly withdrawn. I watched this for a minute or 
two, and then, to my surprise, for I had made no move- 
ment, the female suddenly flew away as if the performance 
had not appealed to her, and the male followed. ^ 

The importance of the scent emitted by male butterflies 
was first recognized by Fritz Muller,^ who described certain 
scales on the wings especially formed for producing scent. 

A very curious and unusual occurrence was noted on 
Bugalla on October 25, 1912, A male of -a small and 
abundant Syntomid moth {Epitoxis albicincfa) was on a 
grass stem, and a male of the common butterfly Acraea 
terpsichore form ventura, in a state of great excitement, 
was endeavouring to effect union with the moth, passing 

^ Trans. Ent. Soc. Lond., 1913, part ii, p. 399 et seq. ; also 1915, part i, 
p. 152 et seq. 

^ For observations showing the relation of these anal tufts to the 
" brands " on the hind wing, see Lamborn, Proc. Ent. Soc. Lond., 1911, 
p. xlvi ; 1912, p. xxxiv ; 1918, p. clxxii. 

» Jen. Zeit., vol. xi. p. 99; Trans. Ent. Soc, 1878, p. 211. 



COURTSHIP OF BUTTERFLIES 223 

the tip of its abdomen repeatedly over that of the moth. 
It was the more curious that there were numbers of freshly 
emerged Acraea females in the neighbourhood with which 
the male butterfly could have mated. Professor Poulton 
suggested that possibly it was a case of accidental likeness 
between the odours of two species very far removed from 
each other, which implies that the male seeks for the odour 
of the female as well as trying to charm her with his own. 

White butterflies of the genus Belenois have often been 
observed courting. A male for a long time flutters round 
and pursues a female, who, perhaps wearied by his im- 
portunities, settles at last with wings expanded. The 
male alights behind her and commences vigorously to 
"paw" her hind wings with quick movements of his 
anterior legs, the action being as if he was trying to walk 
up a very slippery surface. Refusal on the part of the 
female seems to be indicated by a curious attitude. The 
wings are spread out flat, but not quite at right angles 
to the axis of the body, for the fore wings are directed 
slightly backwards. The abdomen is directed vertically 
upwards at right angles to the thorax. 

In 1917 I witnessed the consummation of a courtship 
of a Pierine, the initial stages of which had not been 
observed. A male and female Pinacopteryx simana were 
fluttering in the air and the female suddenly settled, 
quite quietly, and sat with wings closed. The male stood 
over her with wings widely expanded so as completely 
to conceal her ; the union was the act of a moment, and 
then they flew away, the female hanging passively with 
wings closed, the male carrying her. 

Nymphalines such as Precis and Byblia, however, adopt 
different methods of courtship. The female, with wings 
closed over her back, faces the male, who endeavours 
to induce her to allow the union by butting against her 
closed wings with the anterior margin of his own, brought 
together over his back. It appears as if the male's 



224 THE COLOURATION OF INSECTS 

endeavour is to approach from the flank or rear, and the 
female, unless willing, turns so as always to face him. 

In the case of Acraeines little time seems to be wasted 
on persuasion. A male, in the air, makes for the female, 
who at once falls fluttering to the ground, where the two 
seem to struggle together. If the female is willing, union 
is almost immediate ; if not, the male soon flies away. 

On August 2, 1918, in Portuguese East Africa, I saw a 
very good illustration of this. A fresh specimen of Acraea 
natalica was flitting aimlessly about, and I was awaiting 
an opportunity of catching it, when an old and very worn 
female came by. The male at once went to her, and she 
fell straight to the ground. I watched for several minutes. 
The male was very excited, and gripped the female with 
his legs round the roots of the wings, but she lay motionless 
on the ground adopting an attitude of passive resistance, 
the wings folded against her body and pressed closely, 
so as to prevent the male thrusting his abdomen down to 
meet hers, which he struggled to do. After a little he 
managed to pass his abdomen between her wings, but 
she made no response, and he suddenly gave up and flew 
away. I caught him, and then found the female still 
lying motionless on the ground, and secured her too. 

In connection with the pairing of butterflies, the following 
is of interest to evolutionists. 

During the nuptial flight it is known that in the case 
of some species the male carries the female, in other cases 
the positions are reversed, the one that is carried remaining 
absolutely passive with wings closed. In a discussion on 
Sexual Selection among insects in the Descent of Man,^ 
Darwin remarks on some cases where the male is " less 
bright " than the female, ^ and points out that in the 
English Pieris, CoUas and Epinephele janira the duller male 
is supported during the nuptial flight by the female, " so 

^ Chapter xi. 

* The Lycaenid butterfly Lnchnocnema bibulus has a dull brown male 
which is pursued in courtship by the brighter blue-marked female. 



NUPTIAL FLIGHT OF BUTTERFLIES 225 

th.at the part which the two sexes play is reversed, as is 
their relative beauty," and Darwin goes on to say that 
it may be supposed that the female takes the more active 
part in the wooing. Since the middle of 1917 I have paid 
particular attention to this point, and a large number 
of pairs have been noted on the wing. In the Pierines,i 
in all cases save one, the male has carried the female 
as above described. So that it would appear that Darwin 
was misinformed regarding Pierines, unless our English 
species have different habits. My few observations of 
Nymphalines show that the female carries the male. 
This appears alsg to be the case with Lycaenidae. 
Acraeines show no definite rule. In the case of Satyrines 
the female seems to carry the male, and I have seen 
Papilio dardanus form hippocoon carrying the male. 

We now come to the consideration of Mimicry, one of 
the most fascinating subjects for study that insects can 
provide, and one on which a large amount of work has 
been done in recent years, from the point of view of the 
Darwinian hypothesis, thanks to the influence of Professor 
Poulton, of the Hope Department at Oxford. 

The study of mimicry was first taken up by Bates, 
who, on the Amazons, found that a large number of 
abundant butterflies were of the type previously alluded 
to as aposematic, but that others, although superficially 
resembling the former, belonged to groups anatomically 
very different from them.^ 

He put forward the explanation that these latter lived 
on the unsavoury reputations of their associates, or, in 
other words, were Mimics of more distasteful models. 
He found that whereas the models were abundant, easy 
to catch, and avoided by birds, ^ the mimics were less 

1 Proc. Ent. Soc, 1918, p. clii. * Loc. cit. 

* Bearing on this ia the fact that Acrseinea and Danaines rarely show 
evidence of attacks by birds which is so common among Lycaenidae, 
unprotected Pierines or NymphaHnes, Satyrines, etc., in which a ^- 
shaped piece is symmetrically cut out from both hind wings, showing 
the nip of a bird's beak. 

16 



226 THE COLOURATION OF INSECTS 

abundant, shy, and easily alarmed, and there was no 
evidence that they also were distasteful. On reflection 
it is quite obvious that a mimic must be less abundant 
than its model, for if, of a series of conspicuous insects 
met with some are edible and others distasteful, an enemy 
might find it worth while to catch every one he saw on 
the chance of it being edible. If, however, the proportion 
of edible to distasteful is very low, the chance of finding 
an edible specimen is too small to make it worth while 
catching large numbers that will not be eaten. 

The mimic, as has been said, is easily alarmed, and it 
is not difficult to understand the reason. It has been 
pointed out above that aposematic species, which serve 
as models, are extremely resistant to harm, and even 
if caught and tasted do not of necessity suffer vital 
injury. Mimics, however, come from a stock which has 
in the past relied for safety upon concealment or rapidity 
of flight, and have not developed the toughness of their 
models ; hence a nip by a bird's beak or the rough handling 
of a monkey may cause fatal damage. 

So that one finds by experience that so long as mimics 
are not alarmed, they have a great resemblance in move- 
ment and habits to the aposematic species with which they 
are associated. If a mimic is frightened it takes to flight 
and dashes off at a great speed, whereas the model 
will merely move a little way, and often come back 
to the same spot, or may not even deign to move away 
at all. 

Here again is well exemplified the action of natural 
selection in producing changes, not only in colouration 
and shape, but in the nervous system also, yet only so 
far as such changes are required. Thus in certain mimetic 
South American Pierines, a small part of the fore wing 
that is normally concealed by the hind wing retains the 
hue from which this grouji has derived the name of 
" Whites," while the visible areas of the wings are mimetic 



IMPORTANCE OF ATTITUDE IN MIMICRY 227 

of a brightly coloured model. ^ Again, instincts are 
modified so long as the assumed attitudes and move- 
ments are needed to correspond with the false appear- 
ance of inedibility, but when these are no longer helpful, 
rather a danger, the recently acquired instinct of deceit 
is abandoned, and the more deeply seated instinct of 
flight comes into action. 

Attitude is of very real importance in producing 
mimetic resemblance, and living specimens often appear 
mimetic when in the cabinet they do not. So that the 
ignorant remark, which may sometimes be seen in 
print, that mimicry is the product of the imagination 
of an '* arm-chair philosopher " need not be seriously 
considered. 

One day, on Damba Island, I was looking at a nest 
of the tree ant, jEcophylla, among the leaves of a bush. 
This species, by means of silk spun by a larva held for 
the purpose by an ant, fastens together leaves to make 
a more or less globula>r nest about the size of a cocoanut. 
Wishing to obtain a few specimens I proceeded to box 
them, when, to my great astonishment, one of them 
jumped, thus revealing itself to be no ant, but a mimetic 
spider, 2 which had been running about unperceived 
among the ants ! 

The wonderful thing about this case is the great 
anatomical difference between ant and spider, both 
internal and external. The model has head, thorax, 
and abdomen separated from each other by well marked 
constrictions, but the spider has head and thorax fused 
into a cephalo-thoracic mass, separated from the abdomen. 
The ant has three pairs of legs, the spider four ; the ant 
has a pair of long mobile antennae, the spider none. 
Diagrammatically the difference is shown overleaf. 

* Poulton, Essays on Evolution, p. 239. 

2 Myrmarachne Joenissex. Another spider mimic of the same model is 
described and figured by Shelford in A Naturalist in Borneo, pp. 230-1. 



228 THE COLOURATION OF INSECTS 

These dififerences are sufficiently obvious in the dead 
specimens, and the quick nervous movements of a live 
ant with waving antennae are as different as possible 
from those of a typical spider. 

Nevertheless in this case the spider completely deceived 
me. How was it done ? Firstly, the shape is unusual 
for a spider, the cephalo-thorax and abdomen being thin 
and prolonged, and a constriction in the cephalo-thorax 
of the spider represents the division between head and 
thorax of the ant. The spider did not use the first pair 
of legs for walking, but they were held up in the air and 
waved about to copy the movements of the antennae 
of the model. It is obvious that this functional modi- 
fication necessitates a profound alteration in the neuro- 
muscular system of the spider. It is worth noting, too, 
how in the last extremity the spider disclosed its true 
nature in its endeavours to escape by jumping, a habit 
common to the family to which it belongs (Salticidae), 
but suppressed by the new mimetic instinct until an 
emergency arose. This spider wa? not the only mimic 
of ^cophylla, for running among them, and almost as 
closely resembling them as did the spider, was a small 
bug of the family Capsidae} which proved to be not only 
an undescribed species, but sufficiently distinct to be 
placed in a new genus. 

It is of course easier for a bug than a spider to be brought 
to resemble an ant, since both are insects, and natural 
selection has the same basis to work upon. It might 
be supposed that the wings and wing covers of the mimic 
would prove a difficulty, since they lie over the abdomen, 
but in Xenetomorpha there is a constriction near the 
base of the wing covers which, seen from above, matches 
the constriction between thorax and abdomen of the 
ant. The bug lives among its models, probably sucking 
the juices from the stems of the leaves among which 

1 Xenetomorpha carpenter i. 



ax™. 



QjL-dLer»v\4y»v 



M^I 



?ji^ 




SPIDER . 




IMAGINARY CASE OF MAMMALIAN MIMICRY. 
Diaii'ii by Dr. H. Eltringhain. 



IMAGINARY MIMETIC RABBIT 229 

the nest is made. The spider catches flies, and on one 
occasion was actually seen to run into the outer spaces 
of the nest with its prey. The wonderful nature of this 
mimicry of an ant by a spider may be brought out by 
an imaginary, but parallel, example for the benefit of 
those unaccustomed to deal with insects, and unfamiliar 
with the important differences between ant and spider. 
It is probable that tortoises are not eaten by those 
carnivorous animals which prey upon rabbits. Let us 
imagine a farmer in the country seeing what he thought 
was a tortoise, and idly watching it crawling about in 
the characteristic tortoise fashion. He goes up to it and 
frightens it, when, to his astonishment, it bounds away 
with the typical rabbit gait. He shoots it, and on ex- 
amination finds all the essential features of a rabbit : 
it has rodent teeth, but the external ears are so small 
as to be unnoticeable. The main resemblance to a tortoise 
is produced by a matting together of the hair on the 
back to form a carapace-like structure, ^ and on the legs 
to look like scales, while the legs themselves are much 
reduced in length, but very thick. 

A species which " assumes a virtue though it has it 
not " is a true mimic, and is said to be Pseud-aposematic, 
or to have false warning colours, for it appears in the 
guise of another more fortunate than itself in the possession 
of distasteful qualities. But when the mimetic association 
first described by Bates was more fully investigated, 
some of the members were found to be quite as abundant 
as the species which they resembled, and to belong to 
groups which could be claimed to be as well protected as 
the models. It was pointed out previously that a mimic 
must be less abundant than its model. Fritz Muller 
first pointed out how a distasteful and abundant species 
can gain by resembling anothey equally distasteful and 

^ Compare the so-called horn of a rhinoceros, which is structurally 
merely agglomerated hair. 



230 THE COLOURATION OF INSECTS 

abundant. In a brief preliminary statement in 1878 ^ 
he says : " What advantage can it be to a creature pro- 
tected by repellant odour to resemble another similarly 
protected species ? If their foes avoid protected species 
by * instinct,' none at all ; but if, on the contrary, as 
appears so much more probable, the foes have to learn 
their unpalatability by experience, then the benefit is all 
the greater the less numerous the species. The advantage 
gained by two unpalatable species by their resemblance 
is in inverse ratio to the square of their numbers." 

This quotation may be amplified a little. A certain 
number of lives of any species must be sacrificed in 
teaching inexperienced enemies what to avoid. But 
if the loss of insects of a certain definite aposematic 
pattern, instead of being borne by one species only, could 
be distributed over several resembling each other, the 
loss borne by each species would be only a small pro- 
portion of the total loss, while the lesson would be equally 
well learnt. Moreover, it will be of further advantage 
in that there will be fewer patterns to tax the enemy's 
memory. 

So now we have to consider a second type of resemblance, 
characterized by the presence of Common Warning Colours, 
or, to use Poulton's term, Syn-aposematic. Although the 
term " Mimicry," first used by Bates, should refer to 
an edible species masquerading as inedible, it is loosely 
used to cover the likeness between two distasteful species, 
which is a matter of a different order. Properly speaking, 
Mimicry is Pseud- and not /Si/w-aposematic. 

Instances of syn-aposematic resemblance may be seen 
in England, such as the yellow and black bands of different 
kinds of wasps, or the red and green of the Burnet moths. 
These insects being so closely related, it may with reason 
be argued that it is not surprising that Burnet moths 
of a single genus should have a close similarity. 

* See Proc. Enl. Soc. Lond., 1915, pp. xxii, xxiii. 



SYNAPOSEMATIC ASSOCIATIONS 281 

As a better instance may be cited a number of Hymen- 
optera of different groups which I found on the islands, 
characterized by dark grey or dull black colouring with 
a segment of the antennae and the tip of the abdomen 
conspicuously white, and the transparent wings partly 
clouded to form a pattern. Several species of Fossorial 
and Parasitic Hymenoptera were collected that belonged 
to this syn-aposematic association ; in one case, a Scoliid, 
the white on the antennae was produced by white hairs, 
and was not, as in the other species, the colour of the 
integument. This is an interesting example of a point 
with which Professor Poulton has dealt at some length, ^ 
that natural selection has brought about the same effect 
in different ways on different subjects, according to the 
material offered for selection. Natural selection can 
originate nothing ; it can only work with and modify 
material offered to it by variation. This point can never 
be kept too much in prominence. 

The best known syn-aposematic association centres 
round the undoubtedly distasteful and conspicuous Mala- 
coderm beetles of the family Lycidae — such insects are 
very conveniently spoken of as " Lycoid." The Lycid 
aposeme is a general colouration of bright orange-brown, 
with the extremity of the abdomen and elytra black. 
The antennae and limbs are black or black and orange. 
The beetles are found collected in numbers ^ on flowering 
bushes, are of sluggish habit, slow, heavy flight, unafraid, 
and often exude a droplet of yellow fluid when handled, 
and have been proved to be distasteful to vertebrate 
enemies.' G. A. K. Marshall figured 4 a large number 
of Lycoid insects belonging to many orders of insects. 
In beetles and bugs {Hemiptera) the species are coloured 

^ See Essays on Evolution, pp. 2G4-6 ; also Punnett, Mmiicry in 
Butterflies, pp. 40-2. 

2 Proc. Ent. Soc. Land., 1917, p. Ivii. 

» Trans. Ent. Soc. Lond., 1902, Part III, pp. 347, 391. 

« Ibid. 



232 THE COLOURATION OF INSECTS 

in the same way as in the Lycidae. In the clear winged 
Hymenoptera the wings are tinted with orange, and, at 
their tips, with black, so that when brought together 
over the body they produce the Lycoid effect. Lycoid 
beetles are numerous. I have met with them among 
the families Cerambycidae, Chrysomelidae, Cetoniidae, and 
their closer Malacoderm relations, Lagriidae. Of Hymen- 
optera, the fossorial Sphegidae and Pompilidae, true 
wasps, and parasitic Braconidae, all had Lycoid repre- 
sentatives on the islands ; also Hemiptera. 

A small moth, of family Lithosiidae, abounded among 
long grass on Bugalla Isle, and as it rested with its wings 
superimposed upon its back, the resemblance to a Lycid 
was quite striking. This was less so in the case of a new 
species of Zygaenid moth ^ which I was fortunate enough 
to find. The wings were laid along the side of the body 
in the usual Zygsenid manner, so that the fiat appearance 
of the model beetle was lacking. Many of these Lycoids 
could be found at the same time as the Lycid beetles 
on the flowers of Haronga madagascariensis, a tree or 
shrub very abundant on the islands, and known as the 
" Gamboge " tree. 

The Lycid aposeme is not confined to Africa. Shelf ord^ 
gives a long list of Lycoid insects met with in Borneo, 
some of which are syn-aposematic, while others are 
probably pseud-aposematic. 

Mimicry, using the term in its widest sense, it to be 
found with every degree of relationship between the 
insects concerned. I have drawn up a table, from examples 
met on the islands, showing this graphically. At the top 
of the column of species will be found the pair in which 
model (uppermost) and mimic are as closely related as 
possible, being members of the same genus. At the 
bottom of the column model and mimic are as far apart 
as members of the Phylum Arthropoda can be. Between 

^ Saliunca egeria. ^ A Naturalist in Borneo, p. 241. 



MODEL AND MIMIC 



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234 THE COLOURATION OF INSECTS 

these two is a series of pairs, model uppermost, showing 
every grade of relationship. 

Mimicry, looked at from one point of view, is merely 
an example of resemblance to an especial part of the 
environment, and is strictly analogous to special pro- 
cryptic resemblance. Both are forms of Apatetic coloura- 
tion. ^ In one case the insect is like a leaf or twig which 
is of no interest to an insectivorous enemy ; in the other 
it resembles another species which the enemy rarely 
eats, knowing it to be distasteful. There seems no logical 
reason for supposing that the latter example is beyond 
the power of natural selection any more than the former, 
yet in spite of much recent work on these lines by the 
Hope Department, and also by naturalists in the field, 
it is held by some that the resemblances are fortuitous, 
or the result of causes which together or separately are 
not able to explain facts as are the Batesian and Mullerian 
theories, based on natural selection. 

An objection is sometimes urged somewhat as follows. 
Since the potential numbers of patterns are limited, and 
the number of species large, it is quite possible that the 
same pattern may have been accidentally produced in 
two species without there being any meaning to be attached 
to the resemblance, except mere coincidence. 

Dr. F. A. Dixey dealt with this argument at the 
meeting of the British Association at Birmingham in 
1913.2 He showed a number of examples of Lepidoptera 
from different continents with approximately the same 
colouration and pattern, and to these cases it would 
of course be absurd to ascribe a mimetic significance. 
But it is important to note that such coincidence has 
gone no further than to produce the crudest of patterns 
and contrasts, such as a light subapical bar on a dark 
fore wing, and the likeness even then is not so close as 

^ Colours of Animals. See classification at end. 
* See Report, p. 618. 



THE SELECTIVE AGENTS 235 

between species of Planema and their mimics, forms of 
Pseudacraea. 

Coincidence has proved itself unable to produce such 
cases as those in South America described by Bates, 
where the colouration is a comparatively complicated 
mixture of red and yellow on a dark background. These 
cases, indeed, almost seem to be an exception to the rule 
stated above, that aposematic patterns are extremely 
simple. 

The geographical variations of a mimetic species, 
according to the different species serving as models in 
the various subdivisions of its habitat, such as in the 
case of Acraea alciope ^ or Pseudacraea eurytus (see next 
chapter), with the transitional forms at the meeting 
points of two areas, are extremely difficult to explain, 
except by the theory of a causal connection between 
model and mimic. 

One of the great difficulties felt by many to militate 
against acceptance of the theory of mimetic resemblance 
produced by natural, selection is lack of definite evidence 
of a selective agent. It is claimed that it has not yet 
been proved that birds eat butterflies in sufficient numbers 
to produce selective action, and, moreover, that they have 
in certain cases been seen to devour just those species 
which are claimed to be exempt. ^ This latter point has 
been already dealt with. I think that few would claim, 
for instance, that the sting of a bee is of no protection 
to it because the Bee-eaters appear to be especially fond 
of them. A mimetist would account for such cases as 
the ashy wood swallow devouring Danaines in this way. 

Regarding the general question, there is plenty of 
indirect evidence of attacks by birds upon butterflies. All 
collectors must have noted the ^-shaped gaps in the hind 
wings, symmetrical on both sides, that could only have 

» Bedrock, No. 1, April 1912, pp. 57-64. 

* Punnett, Bedrock, vol. ii, July 1913, pp. 159-60. 



236 THE COLOURATION OF INSECTS 

been produced by a portion of the wings enclosed in a 
bird's bill breaking away, as I have previously described. 
As for direct evidence, G. A. K. Marshall first collected a 
number of records of attacks by birds actually witnessed,^ 
but C. F. M. Swynnerton has recently produced such 
overwhelming evidence, ^ that there can no longer be any 
doubt about the matter. His many careful observations 
have shown that attacks on butterflies may very easily 
be overlooked unless an observer is especially on the look 
out for them. 

For instance, the late F. C. Selous said : " I have never 
once seen a bird eat a butterfly in Africa." {African 
Nature Notes and Reminiscences, p. 9.) But I do not 
see that the negative evidence of a hunter, who did not 
pay so much attention to small life as to big game, weighs 
against the positive evidence brought forward by Swynner- 
ton and others, who have paid special attention to birds 
and butterflies from this point of view. 

In fact, Selous's statement only shows how much an 
observer may fail to see outside his particular sphere 
of interest ! 

It appears to me that observation of one class of life 
renders it difficult to observe another ; indeed, there are 
three definite fields, requiring radii of observation of 
different lengths. First, and nearest, are insects whose 
small size renders it necessary to look for them near at 
hand. I find that I instinctively keep my vision on objects 
within about ten yards' radius when I am out in the field, 
insects being my natural prey. Big game can hardly 
be expected to be seen within this area ! If it is desired 
to observe birds, the radius is longer, and one looks not 
on the ground or low herbage near at hand, but at bushes 
and trees at least twice as far away, and for mammals 

» Trans. Ent. Soc. Loud, 1902, Part III, pp. 353-71. 
^ Proc. Ent. Soc. Lond., 1915, pp. xxxii-xliii ; Journ. Linn. Soc, 
1919 ; Zoology, vol. xxxiii. 



BIRDS AND BUTTERFLIES 287 

the radius is much increased, I have often noticed that 
when out for insects I notice very little of the bird life, 
and if I want to see birds have to determine to ignore 
insects. How much the more is this necessary for 
mammals ! 

If an entomologist fails to observe distant game, 
equally so must the hunter, who is looking out for distant 
animals, be oblivious to much that goes on near at hand. 
The habitual gaze of such a practised hunter as Selous 
would be fixed beyond the shorter radius necessary to 
observe small birds and their prey. This seems a possible 
explanation of the failure of a great hunter to see what 
I have seen on several occasions in a fraction of the time 
that he spent in the field. I think, speaking from my 
own experience, that one is too apt only to notice such 
birds which, perched on conspicuous twigs or tree tops, 
look as if they were going to catch butterflies, such as 
Bee-eaters, Drongos, etc. At any rate, that has been 
my error on the islands, and I never saw a Bee-eater 
attack a butterfly, although I found several pairs of wings 
of Terias lying on the ground under a stem where Melit- 
tophagus meridionalis had just been sitting. Had I read 
Swynnerton's work before I collected butterflies, I should 
certainly have seen, as Swynnerton says, " a sudden 
sharp movement at the back of a flower head or the 
quick dash of a bird over the top of a pannicle on which 
butterflies and Hymenoptera may be feeding together ; " 
for birds often flew away at my approach to the flowering 
bushes of Haronga, on which great numbers of butterflies 
fed. 

Since I left the islands I have seen a bush frequenting 
bird, probably Campephaga nigra, the black cuckoo-shrike, 
very quietly eating a Pierine butterfly (Belenois), but 
had I not heard the quick flutter of wings and the snap 
of a bill as it caught the butterfly, my attention would 
not have been drawn to this case. 



238 THE COLOURATION OF INSECTS 

In 1915, while on active service in German East Africa, 
I saw two wagtails at puddles eat eleven butterflies in 
five minutes, and on another occasion saw one eat eleven 
butterflies in three minutes, definitely selecting for its 
food Lycaenidae, Belenois, Atella, from among a crowd 
of butterflies assembled on the mud, and paying no atten- 
tion to a number of the typically aposematic Danaine 
Amauris echeria, or the black and scarlet Papilio 
ridleyanus, mimetic of Acraea egina.^ 

Lastly, it may be said, when dwelling on this question 
whether birds do or do not by eating butterflies cause 
mimetic resemblances, is it not too often forgotten that 
butterflies are not the only mimics ? No one will deny 
that spiders are eaten by birds, or flies, or beetles, or 
grasshoppers, yet numbers of mimetic members of all 
these groups are known, all explicable by the same theory 
as mimicry among butterflies, and all must stand or fall 
together. 

Dr. W. H. Longley has suggested a modification of 
Thayer's views on concealment, supposing that all 
species have been forced to assume colour combinations 
which most effectually conceal them in their normal en- 
vironment ; and that in a few cases patterns have appeared 
which have been sufficiently alike to deceive enemies 
which discriminate in their choice of food.^ This hypo- 
thesis thus evades the difficulty of understanding the 
gradual building up of a mimetic likeness while acknow- 
ledging that mimicry does exist and is of value to the 
mimic, and that different degrees of edibility exist, but 
it affords no explanation of the difference in behaviour 
between model and mimic. If both Planema tellus and 
Pseudacraea eurytus form terra, are equally well concealed, 
why should the former be so bold that it can be plucked 

^ Proc. Ent. Soc, 1915, pp. Ixix.-lxxv. 

'^ " A Revised Working Hypothesis of Mimicry," The American Natural- 
ist, vol. li, May 1917, p. 276. 



LONGLEY'S HYPOTHESIS 239 

from a flower by the fingers, while the utmost caution 
is necessary if one wishes to catch the mimic ? Dr. 
Longley lays stress on the assertion that " colour and 
habit are associated variables," which hardly seems to 
be consistent with the great dififerences in habit between 
model and mimic of the same colour and pattern.^ 

Again, I would point out that it is difficult in the 
extreme to think of all larvae, for example, as concealed 
by likeness to their surroundings. On our common 
hawthorn bush, for instance, caterpillars of the gold 
tail moth, or of the " Figure of eight " moth {Diloba 
caeruleocephala) thrust themselves upon one's notice, 
and side by side on the same bush highly modified 
Geometrid larvae are only to be discovered by careful 
search, so similar are they to twigs. A large Hypsid 
larva (pactolicus) abounded on a papilionaceous plant 
growing on sandy shores of the islands of Lake Victoria. 
It was marked with alternate rings of dead black and 
purest Chinese white, with red head and legs and long 
black or white hairs, and was visible clearly from as 
far away as a creature of that size could be visible. It 
developed into a gorgeous orange moth, with blue-black 
blotches on the fore wings and a black border to the hind 
wings, which was a brilliant and conspicuous object at 
rest or on the wing. It freely exposed itself, and was 
of sluggish habits and slow, heavy flight, as it would be 
expected to be on the Darwinian explanation. Yet 
Dr. Longley would have us believe that it is really con- 
cealed, and offers no consistent explanation of its habits. 

The great attention that is nowadays being paid to 
the principles of heredity as expounded first by Mendel, 
and to the theory of " Mutations," has resulted in 
attempts to account for cases of mimetic likeness by sup- 

^ In the case of the Lycidas the larvae are carnivorous and live in the 
open ; those of a very close Longicorn mimic live in dead wood. At 
the stages when the future similar colours of the adults are being pre- 
pared the habits of model and mimic are as dissimilar as possible.. 



240 THE COLOURATION OF INSECTS 

posing that a mimic was produced suddenly in the likeness 
of some other species, by a large variation known as 
a mutation, and that the Mendelian principle perpetuated 
this unchanged, the pattern, etc., being due to presence 
or absence of certain " factors," or of factors inhibiting 
others. 

. If mimics are produced by mutations, it is remarkable 
that not only superficial aspect, but movements and habits 
should be produced that, quite fortuitously, are extra- 
ordinarily like those of some other species in the same 
neighbourhood, and it seems highly remarkable that such 
mutations should resemble species of the type described 
as aposematic. How is it that mutation does not pro- 
duce new forms resembling procryptic species 1 Why 
should all the females of P. dardanus be modified by 
mutation to resemble different species of conspicuous, 
relatively distasteful butterflies of genera belonging to 
two different sub -families ? Why has not a form of the 
excessively variable species Pseudacraea eurytus (see next 
chapter) been produced that deceptively resembles some 
procryptic species 1 This most wonderful genus has 
only two out of over a score of forms that are not close 
copies of some other butterfly, and yet the species 
resembled are all aposematic ! It seems incredible that 
mutation can produce only pseud-aposematic variation. 
Where, then, are the other less conspicuous forms ? No 
other conclusions seem possible than that they have 
been destroyed by enemies before they could establish 
themselves. If this be so, the argument that insectivorous 
enemies do not destroy butterflies in sufficient numbers 
to have a selective influence falls to the ground. 

As a matter of fact, a few cases are known of such a 
Variety differing very considerably from its parents to 
a degree that could be claimed as an instance of the 
sudden appearance of a mutation. ^ But they are ex- 

1 Bedrock, vol. i, pp. 63-4 — an example of a rare large variation in 
Acraea alciope. 



INHERITANCE OF SMALL VARIATIONS 241 

cessively rare compared with the numerous finely gradated 
forms that may be found connecting a mimetic form 
with a non-mimetic or transitional between two mimetic 
forms. 

That birds do exercise discrimination and do destroy 
large numbers of butterflies there can no longer be doubt, 
thanks to Swynnerton. It seems difficult to avoid the 
conclusion that the conspicuous mimics are ^preserved 
by selection, and it is on the question how they arose 
that Darwinians and mutationists join issue. 

The study of a mimic of wide distribution and changing 
form, such as Acraea alciope, Pseudacraea eurytus, Charaxes 
etheocles, shows by the transition stages that a mimic 
is not suddenly turned out complete. Evidence may be 
found in the publications of the Entomological Society ^ 
that the small, often quite small, variations on which 
a Darwinian depends, are heritable, whereas, according 
to the mutationist, such " fluctuations " are not handed 
down. On the other hand, the mutationist claims that 
his large variations are irrevocably fixed, and, when once 
formed, do not retrogress towards the parent form. Thus, 
for instance, the wonderful forms of Pseudacraea eurytus, 
mimicking different species of Planema according to the 
locality, should, if the model ceased to exert its influence, 
still continue to show the same great degree of resemblance 
without the occurrence of any intermediate variations. 
The next chapter, however, shows that this is not the 
case. 

^ Poulton, E. B., "Heredity in Six Families of P. dardanus, subsp. 
ceneay Trans. Ent. Soc, 1908r Carpenter, G. D. Hale, " The Inherit- 
ance of Small Variations in the Pattern of Papilio dardanus." Trans. 
Ent. Soc, 1914. 



17 



CHAPTER XI 

PSEUDACRAEA EURYTUS 

The Nymph aline genus Pseudacraea is closely allied to 
the more widely spread Limenitis, but is confined to 
the Ethiopian regions, including Madagascar. The name 
is an excellent one ; for out of a considerable number 
of species, although the number has been much reduced 
during recent years owing to the fusion of many " species " 
into one, only two are non-mimetic. The remainder 
resemble for the most part members of the Acraeine genus, 
Planema, a few mimic Acraea itself, one mimics theDanaine 
genus Danaida and others ^mawm. 

One of the most remarkable points in the resemblances 
is the fidelity with which a single polymorphic species 
mimics sundry species of models of very different appear- 
ances in different localities ; and where a model is sexually 
dimorphic the sexes of the mimic faithfully copy the 
corresponding sex of the model. Yet in the very locality 
where this dimorphism of model and mimic exists other 
species of monomorphic models are closely copied by 
monomorphic forms of the same species of mimic. 

The closeness of the resemblance is most remarkable, 
and is indicated by names such as deceptor, simulator, 
imitator, etc. Indeed, as Eltringham saj'-s in his Mimicry 
in African Butterflies, the deception caused Hewitson 
himself, a violent opponent of Bates's explanation of 
these resemblances, to comment upon the strange simil- 
arity between Acraeine and Nymphaline. 

242 



THE FLIGHT OF PSEUDACRAEA 243 

I have many times been deceived by these mimics 
in the forests on the islands, until long association and 
close familiarity enabled me to differentiate. But even 
then, after a pause of a few weeks during which they 
had not been seen, it was by no means easy to say 
at a glance whether a specimen seen suddenly in the 
forest was Planema or Pseudacraea. Certainly the mimics 
are not so bold as Planema, and if really alarmed will 
show it in their hasty flight, whereas the model is much 
more stoical, and may be easily picked off a flower with 
the fingers. 

The flight of Pseudacraea is often of the " floating " 
nature, especially when several of these butterflies are 
flying rather high up, in the sun, and round about a tree. 
By this the mimic can be distinguished, but some species 
of Pseudacraea, e.g. poggei, do not show the " floating " 
flight to the same degree, and thus poggei bears an even 
closer resemblance to its model, Danaida chrysippus, 
whose flight is much more of the " flapping " type. 

Professor Poulton has written as follows about this 
flight in a letter dated September 5, 1912 : "I am very 
interested in the non-floating flight of the most distaste- 
ful butterflies. But I have seen a kind of floating flight 
in D. plexippus in America. Still this is not like our 
Limenitis, and this latter I suspect is like Pseudacraea. 
A floating flight for display, accompanied by alertness 
and activity when alarmed, seems to be characteristic 
of the second category of distasteful insects in Mullerian 
combinations ; it is also true of the true Heliconinae in 
South America, mimics of the Ithomiinae." Again, in 
another letter, written March 6, 1912, Professor Poulton 
said : "It is an extraordinarily interesting genus ; its 
habits, I should think, are rather like those of our 
Limenitis, and the degree of distastefulness I should 
think about the same." 

The genus Pseudacraea, therefore, is to be regarded as 



244 PSEUDACRAEA EURYTUS 

an example of the " transition from Warning to Mimetic 
colours " described by Poulton in the Colours of Animals, 
pp. 221-223, that is, these butterflies possess a certain 
degree of distastefulness compared to some others, but less 
than others which they resemble, and so benefit by the 
more unpleasant reputation of these latter. They are 
Syn-aposematic and not Pseud-aposematic : MuUerian 
and not Batesian mimics. 

I have noticed a peculiar sheen on the wings, especi- 
ally on the under surface, that has been found very 
useful in enabling me to distinguish the nature of a 
specimen seen sitting far out of reach on a leaf in the sun. 

The forms with which we are concerned in this chapter 
frequent forest, and are not to be found outside. But 
flowering shrubs at the edge of a forest will often prove 
extremely attractive, so that Pseudacraeas will collect 
thereon in numbers, coming from the shady forest to 
the bright sun at the edge, when they may be found 
on the flower heads until shortly before sunset. On 
Bugalla Isle, in 1912-13, I had a favourite walk along 
the edge of the forest between 4- 30-6 p.m., visiting the 
gamboge trees [Haronga madagascariensis), which, when 
in full bloom, suppHed many fine Pseudacraeas, Planemas, 
and insects of many other kinds. 

It is not proposed to mention here more than the 
forms of eurytus which occur in Uganda, together with 
the first known form, now known as eurytus itself, in 
West Africa, and the Eastern and South African forms. 
The valuable paper by Dr. Karl Jordan at the first 
International Congress of Entomology ^ and the beauti- 
fully illustrated book by Dr. H. Eltringham on African 
Mimetic Butterflies, will enable the reader to gain some 
idea of the most wonderful polymorphism of this species. 

Dr. Jordan (loc. cit.) figures thirteen West African 

males " considered to belong at least to seven distinct 

species," but says that "as a result of my inves- 

1 lere Congr^a International d'Entomologie, Bruxelles, Aout, 9110, 
pp. 385-404. Plates zzi.-xziv. 




,..??;5 .>'*.;■ >-^.--^ 






-••^ 






PLATE n 

1. Plattema aganice form montana ^, Ngamba Island, L. 

Victoria, 11 vii, 1914. 

2. Psendacraea eurytus form rogersi ^ (the type specimen). 

Caught by Eev. St. A. Rogers near Mombasa, November, 1906. 

3. PI. aganice form montana $ , Tavu Island, 1 vii, 1914. 

4. Ps. eurytus form rogersi ? (the type specimen). 

Caught near Mombasa, 28 vu, 1906. 

6. PI. aganice form nyascs ^ , 13 vi, 13. 

Caught by S. A. Neave on Mt. Mlanje, Nyasaland. 

6. Ps. eurytus form mlanjensis ^ , 11 xii, 13. 

Caught by B. A. Neave on Mt. Mlanje, Nyasaland. 

7. PL aganice form nyasoe ? , 10 vi, 13. 

Caught by S. A. Neave on Mt. Mlanje, Nyasaland. 

8. Ps. eurytus form mlanjensis ? , 17 iii, 13. 

Caught by S. A. Neave on Mt. Mlanje, Nyasaland. 

9. PI aganice 3' , 13 iv, 1897. 

Caught by G. A. K. Marshall, Malvern, Natal. 

10. Ps. eurytus form imitator c? , 7 v, 1910. 

Bred by the late A. D. Millar, near Durban, Natal. 

11. PI. aganice ? , 22 iii, 1896. 

Caught by G. A. K. Marshall, Malvern, Natal. 

12. Ps. eurytus form imitator ? , 20 iv, 1910. 

Bred by the late A. D, Millar, near Durban, Natal> 



m 





2il ^ 

. , , ^ in the ' 

.s, these butterflie ■ 

eiulness compared to S' 

1,1 1- 1 . ., , . 

... ., n aTAJi 

feyxi-aAjoBejnatic aa.l not Pseud- aposematic : Arulieriaii 

.(namioeqe sq^i arid) *& h'ta^o'^ miol ^wi^'tvsi) jiaj>"vooS»V'a«^ ■,.8-\' 
,3061 ,iedmevoPl .BSBcfmoM lijon aiogoH .A .i8 .79H ^'J iiisu^P 



S'lJ 



.^ISI ,117 I ,i)flBl8l uvfiT ,,$ jDipi«ow miQi ^o\««^ sS!i .8 



, J .9061 .117 8S,«BBdmoM 3fl9xi WauaO 

frequei , and are 

flowering shrul- ' '^^ '^^ ^.^ '"^ ^^^^"^ raionf>w»^ .Sa .6 . 

extremely attramj v ::V, .-^ •■■^r. . .■■..■^. ^ .•■- ....■ ■•." .. ..i--. 
thereon in nuir'^f r^^^ ^■'■^■" ^ ^^^m^^^ -o^^oi . a>Ji^-vwS. ,z^, %8 1 r > 

.DaBlBa«i(PI ,9J;n*IM .JM 00 ovbqTI .A .Q ^d jJdgifBO ^• 
the bridv ^^ ^^ ' ■'''■;'-' ,« „ 

,81 <iv 01 ,,$ joani^sr xinQj aoswftigt) .ri .v 

.bnjslfigBYH ,-)[aiillli .iM co av^eH .A .8 x:d JrfgufiO 

.81 ,111 YI ( 2 ^V^«3\i<i)\«f mioi 2wi\y;ma .el .8 
.6aeIjs8B^K ,3[afiIM .IM no . '. .M a g ^^d ddgufiO 

itl tui; .IjBifiK ,ai97lBM .ilBjdieiBM ./I .A .-d^'d dHaufiO ' 

and in.. - qjqj- ,v 7 ^ '^ -TOh^iMuj miol eisi^-^ii^ ,.,5^^, .0^ . 

It is not ^BU,a&d^uaiea'a'^^^Ui^i',a'.'As'i^>\'^r^'f\j^ 

forms of eurytus which occi^^^^ U^ ,^ 

the first known j|ji^ jni^T^laTte ^li&MidiS. .a ,a .i - va hx^^ubj 
We?t Africa, anjj^j^gj- ,,j qj> ^ ^ -^oJ^Vvi^^j mioi zwivvwa .&^ SI 
alliabl«.lBiB>l .aedioa i«on .ibUIM ,a .A aisl adi \(d baiQ. 



lefl«t to ft 
speoi' 



PLATE II. 



Arm fjne rrw <1t>]s 



V \ ■ mp h aJiTie -inimics . 




li C Kivight del. et chromo |j.,^.;^-„ .j^p 

MODEL SPECIES OF PLANEMA WITH MIMETIC FORMS OF 
PSEUDACRAEA EURYTUS. ^ncut. size. 

ReprodjLC^ ly perrrusstorL of th& Fntornologuxcl Soaeiy of LonAorv. 

(To face-Pacfe. 24-6). 



THE TYPE 245 

tigations I must regard these insects as forms of only 
one single species, Pseudacraea eurytus (Linnaeus, 1758)." 
Along with these forms of one species are figured thirteen 
different species of Planema, each a model for a form of 
eurytus ; and on another plate " five white banded female 
specimens of Pseudacraea eurytus, together with the 
females of five species of Planema.'''' 

Pseudacraea eurytus ^ itself was named by Linnaeus in 
1758. It is sexually dimorphic. The male is tawny 
orange and blackish brown, the female black and 
white, with the white areas roughly corresponding to 
the pattern of the orange in the male, but being more 
contracted on the hind wing. It is a West African form, 
mimicking the West African dimorphic species Planema 
epaea. 1 have, however, taken on Bugalla Island a single 
female closely approximating to the typical eurytus ; 
it is intermediate between two forms described below, 
namely tirikensis and terra, having the fore wing pattern 
of terra, but the black and white colour of tirikensis, while 
the pattern of the hind wing closely approximates to that 
of eurytus and thus differs from the pattern of tirikensis. 

In 1919, in a small isolated patch of forest on the 
Kyagwe (mainland) north coast of the lake, I took a 
fine male which is not essentially different from the 
typical male eurytus. 

All the Pseudacraeas mentioned in this chapter, 
except kuenowi, are now known to be forms of eurytus, 
using the name in its widest sense. It has a distribution 
throughout the tropical and subtropical forests of Africa, 
from west to east, and from northern Uganda to Pondo- 
land, south of Natal. It is, however, very scarce in 
East Africa and Rhodesia, 

The form imitator was described from Natal by Roland 

Trimen in 1873 : it mimics Planema aganice and, like 

the model, is sexually dimorphic, although the difference 

in colour between male and female is not so marked as 

^ See the two coloured plates for illustrations of models and mimetic 
forms of this species. 



246 PSEUDACRAEA EURYTUS 

in the first named form. Colonel Bowker, in a letter 
to Trimen, said it was " quite impossible to distinguish 
between this butterfly and aganice either when settled or 
on the wing." (Plate II, figs. 9-12.) 

The male and female have the same pattern on a 
black ground, the pattern being cream coloured in the 
male, while in the female it may be either cream coloured 
or white. The female may thus resemble either the 
male or female of the model, which, so far as I am aware, 
does not occur among other forms of eurytus, in which, 
if the model is dimorphic, the male is copied by the male 
of the mimic and the female by the female. The white 
areas of the female differ quite noticeably in this form 
from the pattern of the female eurytus, there being only 
a trace of white, instead of a large, well defined area 
on the inner margin of the fore wing. This species 
possesses in a very high degree a most conspicuous aposeme 
on the underside of the base of the hind wing which, 
as in the model, must be of great value when the insect 
is at complete rest with the wings brought together over 
the back. This aposeme takes the form of a well defined 
patch of bright purplish or reddish brown, extending 
outwards from the base along the costal margin. 

The form imitator, southern in distribution, is con- 
nected with the northern forms shortly to be described 
by forms found in Nyasaland quite plentifully, and others 
more rarely in East Africa. 

Very recently has been discovered a single specimen 
of a most remarkably interesting form which extends 
our knowledge of the distribution of Pseudacraea eurytus 
south of Natal to West Pondoland. The specimen 
referred to is in the museum at Tring, and I am greatly 
indebted to Lord Rothschild and Dr. Karl Jordan for 
the loan of it that I might compare it with others. It 
was taken on April 16, 1915, by H. H. Swinny, at Port 
St. John's, and is of quite a distinct reddish orange tint, 



A UNIQUE SOUTHERN SPECIMEN 247 

which renders it markedly different from any other form 
of eurytus yet known. It seems to combine the features 
of the western eurytus male with the imitator of Natal. 
The subapical orange area of the fore wing is small and 
narrow, as is the corresponding pale area of imitator^ 
and the inner marginal area on the fore wing is like that 
of eurytus. The hind wings have a very large orange 
area with only a narrow black border, as in the western 
eurytus, but at the base they show the very large purplish 
brown aposeme extending along the costal margin to 
the tip as in imitator. This most interesting specimen 
is a male, and one awaits the discovery of its female 
with enthusiasm : probably it will be black and white. 
It presumably mimics a local form of Planema aganice 
which has yet to be discovered. 

In 1904, S. A, Neave described four new Pseudacraeas 
from Uganda, which are now known to be all forms of 
eurytus, using the name in its wide sense. The form 
hobleyi was the first to be named, and the others make 
with it a group inhabiting Uganda, although some at 
least extend their range out to the West Coast. Hobleyi 
is a male form only, mimicking the male of Planema 
macarista.^ On a ground of blackish brown it has a bright 
orange bar bent at an angle, crossing the fore wing, and 
a white bar crossing the middle of the hind wing. This 
latter bar, however, as in the model macarista^ is often 
bordered with orange-brown and, in examples brought 
by Neave from Western Uganda, becomes wholly orange. 
This form appropriately mimics the local form of Planema, 
in which the white bar of macarista is replaced by orange. 
This is Planema pseudeuryta, very closely alHed to 
macarista. The form hobleyi has a basal aposeme on 
the under surface of the hind wings, but this differs 
sUghtly from that of imitator, being more concentrated 
into a basal triangle, and of a more reddish and less 
1 Plate I, figs. 5, 6. 



248 PSEUDACRAEA EURYTUS 

purplish brown. Needless to say, this aposematic triangle 
is a very marked feature in the model macarista. 

The shape of the orange bar crossing the fore wing 
of hobleyi varies considerably, and in some cases bears 
a resemblance to the rather dijfferent shape of the bar 
in a very different species of Pseudacraea, namely, Ps. 
kuenowi, which has the same general scheme of colouring. 
It seems possible that these forms of hobleyi show the 
secondary resemblance of one species to another, both, 
however, mimicking the same model, which is found 
and has been described by Dr. Dixey and Professor 
Poulton in other combinations. It would be necessary, 
however, before accepting this for a fact, to ascertain 
whether the proportion of hobleyi with the bar like that 
of kuenowi is greater in the areas where both are found 
together than in areas where kuenowi does not occur. 

Another form of eurytus, described at the same time by 
Neave as a different species, is a black and white female 
known as tirikensis. Later this was found to be the 
female of the male described as hobleyi, and the name 
tirikensis fell into abeyance. Now, however, that both 
are known to be not a distinct species but only forms of 
eurytus, the name tirikensis again holds good as a mimetic 
form name. This female form has a black ground ; on 
the fore wing is a white bar bent at an angle, but the 
posterior end of this beyond the elbow is often so suffused 
with black as to reduce the bar to a large subapical area 
only. Such a pattern very closely resembles that of the 
female Planema macarista, also found in Uganda flying with 
the mimic. The hind wing is black and white, and shows 
well the umber triangle at the base on the under side as 
in the model. (Plate I. figs. 7, 8.) 

This form is very variable, and graduates into others. 
Thus a form from Gaboon, copying the female Planema 
excisa, has the fore wings like those of tirikensis, but the 
hinder end of the white bar is tinted dull yellow, and the 



FORMS FROM NYASALAND 249 

hind wings are pale yellowish, approaching those of such 
a form as terra, to be described below. 

Another specimen in the Tring museum, from Fort 
Anderson, Nyasaland, although it might be termed a 
tirikensis, has a much larger area of white on the hind 
wing, whereby it approaches to the East African form 
rogersi, yet to be considered. 

Dr. S. A. Neave has discovered on Mount Mlanje in 
Nyasaland a form of Planema aganice differing markedly 
from the more southern Natal form by the greater size 
of the pale areas on all wings in both male and female. 
It is copied closely by a corresponding form of Pseudacraea 
showing the same differences from the Natal form,^ 
which is most interesting, for the shape and size of the 
subapical white bar on the fore wing in the female comes 
near to the form of tirikensis whose white transverse 
bar is suppressed at the posterior end, while on the hind 
wing the white area is as in the female form rogersi of 
East Africa, At the base of the hind wing beneath 
there is a large brown aposematic patch, which is exactly 
intermediate between the long narrow purplish brown 
patch of the southern imitator and the more triangular, 
umber-brown patch of tirikensis. 

This new form in Nyasaland is thus beautifully tran- 
sitional between the more northern and the eastern forms 
tirikensis and rogersi and the more southern imitator, 
and agrees as closely with its local model form of Planema 
as do other Pseudacraeas already mentioned. 

At the time when hohleyi and tirikensis were looked 
on as male and female of a distinct species of Pseudacraea, 
a very interesting form was described by Poulton in 
his paper on the Wiggins collection ^ as a " female pos- 
sessing the colour and to a large extent the pattern 
of the male." That is to say, it has an angular orange 
bar crossing the fore wing, but the direction and shape 

1 Plate II, figs. 5-8. 

2 lere Congr^s International d'Entomologie, Bruxelles, Ao<it, 1910. 



250 PSEUDACRAEA EURYTUS 

of the bar is that of the white bar of the female form 
tirikensis in its most complete development : the colour, 
however, is not the rather deep orange of macarista, but 
the paler yellowish orange of the different species Planema 
poggei, of which both sexes are alike, and in which the 
direction of the orange fore wing bar is much more oblique 
than in the male Planema macarista.^ The form of 
Pseudacrdea now under discussion is thus brought to be 
a mimic of poggei rather than of the male macarista both 
in colour and direction of the bar across the fore wing, 
the obliquity being given to the bar because it is of the 
shape of that in the female form tirikensis, and not of 
the male hobleyi. 

It is now incorrect to speak of a " female hobleyi 
with male colouring " with this difference in shade 
in the orange bar, and this form has been named 
poggeoides by Professor Poulton.^ It is remarkably 
interesting from the point of view of geographical 
distribution. The models Planema macarista ^, and 
PL poggei <^ ^, occur around Entebbe, but the 
former is there more abundant and Pseudacraea eurytus 
form poggeoides is very scarce, the females being almost 
all of the form tirikensis mimicking the black and white 
female macarista. But around Mount Elgon, in the 
north-east of Uganda, Planema poggei completely replaces 
macarista, which is not as yet known to occur east of 
the Nile, and the black and white female forms tirikensis 
are outnumbered by the form poggeoides with orange 
bar across the fore wing like the model.' Since the male 
of the mimic (hobleyi) has the bar on the fore wing orange, 
the change in proportion of the two model Planemas 
does not affect its appearance. 

Thus, in the case of the female forms poggeoides and 
tirikensis, there is an exact parallel to th^ case of the 

1 Plate I. figa. 9, 10. - Proc. Ent. Soc, 1912, p. cxvii. 

' Ibid., pp. Ixx.-lxxi. 



FORM TERRA 251 

male form hobieyi already discussed. In the centre of 
Uganda a few forms are found which, in the case of the 
male, become the predominant form to the west, in the 
case of the female become the predominant form to the 
east. In each case the alteration between the proportions 
of the forms coincides with the different proportions of 
the Planema models on the west and east sides of Uganda. 

Another form that was described by Neave in 1904 
from the collection made by C. A. Wiggins in the environs 
of Entebbe is known as terra. (Plate I, figs. 1, 2.) 

This form is monomorphic, male and female alike 
showing a rich orange pattern on a brownish-black ground, 
mimicking to an extraordinary degree of perfection the 
abundant Planema tellus eumelis, which is also mono- 
morphic, although its West African form has a black and 
white form of female as well. The pattern of the form 
terra is much like that of the male eurytus, save that 
the subapical and inner marginal orange areas on the 
for£ wing are more extensive : the colour, however, is 
a much lighter orange. But forms of terra with con- 
tracted fore wing areas are quite common on the islands, 
and one such, mentioned previously, that was taken in 
1919 on the Kyagwe coast in an isolated area of forest, 
had such dark brownish orange colour that it was prac- 
tically indistinguishable from a typical male eurytus from 
the West Coast. In terra there is no basal aposematic 
umber-brown triangle on the under side of the hind wing, 
and this is absent from the model Planema tellus also. 
The form terra is found from Uganda to the West Coast. 

I consider it to be the most perfect mimic of all the 
forms of eurytus that I have seen alive : in pattern and 
colouring it approximates so closely to the model tellus 
that I have been deceived by it over and over again. 

On the islands many variations have been found, 
showing some very distinct patterns and transitions to 
other forms. A common variation is reduction in breadth 



252 PSEUDACRAEA EURYTUS 

of the black bar separating the orange areas on the fore 
wing, and when this is completely eliminated the form 
described by K. Griinberg ^ as a distinct species 
" impleta " is obtained. It would not require a great 
change to develop the male form of rogersi ^ from impleta. 

Another form known as obscura was also described 
by Neave in 1904, and is one of the group from Uganda 
coming under the subhead of hobleyi. This is also a 
monomorphic form, male and female being alike, as are 
the models, the eastern form paragea of Planema epaea, 
a common West Coast Acraeine.^ The model is rather 
rare, and the mimic obscura is also rare. It has pale 
creamy markings, easily derivable from those of terra, 
but much smaller, on a dark greyish brown background. 
The pattern of these creamy markings does not follow 
so exactly the pattern of the model as does that of terra, 
but the general effect is decidedly that of resemblance. 
As regards flight, there is much more difference between 
model and mimic in this case than with the other members 
of the hobleyi group, for paragea the model has rather 
a weak fluttering flight, and looks a feebler insect than 
the robust and powerful Pseudacraea. 1 have never 
mistaken obscura for its model. Both show a certain 
amount of reddish brown at the base of the under surface 
of the hind wing, but this is of a paler tint than the rich 
umber that makes the characteristic basal triangle of 
hobleyi, tirikensis, poggeoides and their models, and is 
not so sharply defined. 

The form obscura seems to be the least fixed of the 
Uganda forms of eurytus comprising the hobleyi group ; 
at any rate, on the islands it was quite difficult to obtain 
two that were closely alike and did not show transition 
to one of the other forms. 

Lastly, there is the extremely rare and little known 
form from near Mombasa, British East Africa, described 

^ Sitzungsber. d. Oes. NaturJ. Freunde, Nr. 4, 1910. 
2 Plate II, fig. 2. 3 Plate I, fig3. 3, 4. 



FORM ROGERSI 253 

as rogersi after its captor, by Trimen in 1908.^ The form 
is dimorphic, the male having the wings blackish brown 
and orange, but the orange is of a slightly more reddish 
tint than in other forms, and approaches the hue of the 
unique specimen previously mentioned from West Pondo- 
land. There is an irregular area on the fore wing like 
that in some of the varieties of terra in which the black 
bar is broken through. 

The black and white female has a pattern after the 
style of the typical female of the western eurytus, except 
that the white area on the hind wing is very much larger, 
and sharply outlined by a narrow black border. There 
is a certain amount of reddish suffusion on the under 
surface of the base of the hind wing. 

This form, rogersi, is represented in collections by a 
single male and female at Oxford, the types. When I 
was recently looking through Lord Rothschild's magni- 
ficent collection of Pseudacraea eurytus at Tring, I found 
there were three females bearing labels " Mombasa " 
that appear to be of this form, but I do not know of any 
other males. 

The only Planema of abundance in the locality from 
which this form is known is Planema aganice, in its 
eastern and northern form montana? In this form the 
sexes are different and much more unlike than those 
of the southern aganice ^ which, be it remembered, served 
as model in Natal for the form of Pseudacraea eurytus 
known as imitator. In aganice montana the male, instead 
of having a creamy yellow pattern, has the same areas 
of a rich orange. In the form rogersi now under dis- 
cussion, the pattern is not quite like that of Planema 
aganice montana, and is much nearer that of another 
species of East African Planema, viz. adrasta. This 
species has, in the male, a complete orange bar across 
the fore wing, and the female has the very large sharply 
marked white area on the hind wing. Specimens of 

1 Plate II, figa. 2, 4. « Plato II, iSga. 1, 3, » Plate II, figs. 9, 11. 



254 



PSEUDACRAEA EURYTUS 



adrasta in the Tring museum come from Usambara, but 
it appears at present too rare to be claimed as a model 
for rogersi, although the latter resembles it much more 
closely than it does montana. In colouring, however, 
the male rogersi approaches closely enough to the male 
of its model, and the black and white female is a close 
mimic of the female aganice montana. 

The following table shows at a glance the models and 
mimics hitherto dealt with, arranged in geographical order 
from the west to the east coast and then southwards, each 
type of colouring and pattern having a row to itself. 



Species of Planema. 



(? ? 



epaea (J 
epaea $ 
tellus eumelis 
macarista (J 
macarista ? 
macarista pscud- 

euryta (J 
epaea paragea ^ ? 
poggei cj $ 



9. aganice tnontana ^ 

10. aganice montana $ 

1 1 . aganice nyasce. • cJ 

12. aganice nyasce ^ ? 

13. aganice ^ 

14. aganice $ 
16. aganice ^ (?) 



Forms of Pseudacraea 
eurytus. 



eurytus (J 
eurytus $ 
terra (J ? 
kobleyi (J 
tirikenais $ 
form of hobleyi ^ 

obscura <J ? 
poggeaides $ 

rogersi ^ 
rogersi $ 
mlanjensis (J 
mlanjensis $ 
imitator cJ 
imitator ? 
form of imitator ^ 



Distribution (roughly) 



W. Africa 

W. Africa 

W. coast to Uganda 

W. coast to Uganda 

W. coast to Uganda 

W. border of Uganda 

Uganda 

Uganda, especiallyto 

its E. 
Mombasa, E. coast 
Mombasa, E. coast 
Mt. Mlanje, Nyasaland 
Mt.Mlanje, Nyasaland 
Natal 
Natal 
W. Pondoland 



We have here fifteen forms of one species of Pseudacrdea 
mimicking eight different species or subspecies of Planema. 
Specific names were also given in the past to a large 
number of other forms of Pseudacraea eurytus on the 
west coast of Africa differing from the above, although 
easily derivable from them by transitional varieties 
known to exist, and these bear equally close mimetic 

* The names nyasce and mlanjensis have been chosen to distinguish 
these geographical races of model and mimic. 



EARLY EVIDENCE OF CONSPECIFITY 255 

resemblance to different species of West African Planemti. 
(See Dr. Jordan's paper, already cited.) 

It will be interesting now to trace the development 
of our knowledge of this most fascinating polymorphic 
species. 

Professor Poulton, in a letter to Nature, August 28, 
1912, stated : "A little more than two years ago Dr. 
Karl Jordan informed me that he had been studying 
the male genital armature of the Pseudacraeas, and that 
he could not find any difference between the ' species * 
of a large group made up of Linne's eurytus and its 
numerous allies on the West Coast, of Neave's hobleyi 
terra and obscura in Uganda, of Trimen's rogersi of the 
Mombasa district and his imitator of Natal." 

The provisional conclusion drawn from this fact was 
that these butterflies are conspecific, and this was brought 
before the first International Congress of Entomology 
at Brussels by Dr. Jordan in August 1910. 

At the same congress Professor Poulton gave a statis- 
tical study of the large collection made near Entebbe in 
Uganda by Dr. C. A. Wiggins, and stated that in this 
were two specimens which tended to confirm Jordan's 
anatomical findings. One was " a male Ps. terra with 
a pattern approaching the male of Ps. hobleyi,'^ the 
other " a female Ps. hobleyi bearing the mimetic colours 
of its own male " (this is the form now known as 
foggeoides). (Plate I, fig. 10.) 

Quotations from letters that I received from Professor 
Poulton after work was commenced on the islands in 1911 
will show how keenly interested he was in the problem, 
and how important he considered it. 

I first met with Psevdacraea eurytus on Damba Island 
in 1911, towards the end of my stay there, and, not know- 
ing anything about it, found this mimetic butterfly very 
puzzling. Not only was it difficult at first to distinguish 
the forms from their models, but they showed such varia- 



256 PSEUDACRAEA EURYTUS 

tion that it was difficult to assign specimens to any 
particular form, for a single specimen often appeared to 
be transitional between terra, hohleyi and obscura. The 
model species of Planema were extremely scarce on 
Damba, and this point proved to be of great significance. 

A letter from Professor Poulton, dated October 30, 1911, 
referring to the arrival at Oxford of the first consignment 
of these intermediate Pseudacraeas, said : " They looked 
most interesting, and perhaps here your island forms 
will be different and throw light on the polymorphism 
of this set of forms." 

November 9, 1911. — " You have the Pseudacraeas abun- 
dantly evidently, and it is of the utmost importance 
to breed them from known parents. They tend to be 
far more intermediate than on the mainland. I suspect 
that selection of them is somewhat relaxed on the island, 
and they at once tend to mix. You have terra and 
hohleyi ? (I've not seen <? yet) and another form, 
obscura, and transitions of the most beautiful kind 
between obscura and terra, and between obscura and 
hohleyi ? . I've only seen now among your specimens 
the models of hohleyi {Planema macarista 3' and ? and 
PL poggei), but no models as yet of the other two {terra 
and obscura). Now if these models are rare or absent 
perhaps we have the cause of the varieties of obscura 
and terra, viz. a consequence of freedom from rigid 
selection. It is an exciting problem, and you are 
evidently in a most interesting locality." 

November 12, 1911. — "This is the exciting thing; 
there is no doubt that the Pseudacraeas tend to lose their 
distinctness in the absence, or rarity, of their models. 
It is most interesting and entirely supports Dr. Jordan's 
views. I cannot tell you how pleased I am." 

These specimens from Damba Island were exhibited 
at a meeting of the Entomological Society of London on 
December 6, 1911, by Professor Poulton, who said: 



EARLY CAPTURES ON DAMBA ISLE 257 

" I suggest that, in an area where these mimetic 
patterns are less strongly selected, there is a tendency, 
checked elsewhere, for them to run into each other, and 
also to move in the direction of the western eurytus 
forms, from which there can be little doubt that the 
mimetic Pseudacraeas of Uganda originally developed. 
It is to be hoped that Dr. Carpenter may be able to 
obtain the material by breeding, as well as by capture, 
by which this hypothesis will be confirmed or refuted." ^ 

The following table gives at a glance the forms and 
varieties of eurytus, with their models, that were taken 
on Damba : 



Models. 

Planema poggei . . 
„ macariata 
„ epaea paragea . 
„ tellus ewnelia . 

Models 



16 



Mimetic fonna of eurytus. 

poggeoides . . . . — 1 

hobleyi 5 — 

tirikensis . . . . — 4 

obscura 2 1 

terra 6 9 

Mimics 28 

Intermediates . . 10 

Total eurytus . . 38 



It is seen that the mimics are almost twice as numerous 
as the models, and there are in addition more than one- 
third again of forms intermediate between the mimics. 
The total number of Pseudacraeas is more than twice 
that of the Planemas. Concerning these specimens Pro- 
fessor Poulton wrote January 1, 1912 : ** I am most inter- 
ested to hear that you did not distinguish the Planemas 
and Pseudacraeas (I do not wonder at it) : it makes the 
results more conclusive. There must be, I conclude and 
argue in this little paper, something unfavourable to 
Planemas in the conditions of Damba Islands ; and in 
their absence or scarcity selection is damped down and 

^ Proc. Ent, Soc, 1911, p. xciv. 
18 



258 PSEUDACRAEA EURYTUS 

the forms are beginning to run into each other and also 
to assume entirely different proportions from those of the 
mainland. It is most interesting and indeed exciting." 

Early in 1912 I moved camp to the north-east corner 
of Bugalla Island, the largest of the Sesse archipelago in 
the north-west corner of the Lake. The north-west 
promontory of this island almost touches the mainland 
coastline at the port of Bukakata (see map). 

It very soon became apparent that all the combinations 
which were of so great interest at Entebbe and on Damba 
Island were present here, and on March 16, 1912, Pro- 
fessor Poulton wrote : 

" I am very glad that Sesse is turning out to be so 
interesting, and I quite think now that it will be even 
more interesting to compare these two groups of islands 
together rather than to get evidence from only one. You 
will realize the utmost importance of catching all the 
models and mimics you can secure on given days without 
any selection, so that we can estimate the proportions 
of models and mimics and see whether, as in Damba, 
the mimics are relatively far more abundant than on the 
mainland, and whether, as also in Damba, the inter- 
mediates are specially prevalent. 

If the results in Damba are supported by a large col- 
lection on Sesse, I think the matter will really be estab- 
lished, and will constitute the strongest argument I 
know for the origin and maintenance of mimicry by 
natural selection ; for directly the models are reduced 
the mimics begin to run into each other. I think, in 
your case, when you are necessarily pressed with other 
work, that it would be best to concentrate attention on 
the most important problems, and those certainly are 
the proportions of models and mimics and the compo- 
sition of the mimetic Pseudacraea group, and breeding 
the latter to prove that they are all one." 

April 6, 1912. — " How splendid that the problem is 



VARIOUS FORMS COURT EACH OTHER 259 

more illuminated at Sesse than Damba. I never thought 
that I should get such evidence of the effect of a model 
on its mimic, ... It is very important that the Wiggins 
Pseudacraea mimics come from several localities near 
Entebbe and yet never approach your island forms in 
being intermediate, or resemble their proportions to each 
other or to the models." 

I began to try to obtain ova from captured females 
placed in a box in the ft>rest, but although I knew the 
genus of tree on which they would probably oviposit 
{Chrysophyllum, Sapotaceae), it was some time before I 
discovered it in the forest. It may be said here that 
Miss Fountaine has published ^ beautifully coloured draw- 
ings of the early stages of the form imitator, which is the 
only representative in Natal. 

But breeding this form has thrown no light on its 
genesis, or on the other forms. For, since there is only 
one Planema to act as a model, imitator appears to have 
become more fixed than the forms of hobleyi in Uganda, 
and varies very little. 

Meanwhile, I had often seen the various forms in 
Uganda flirting with each other in the manner character- 
istic of male and female of the same species. The follow- 
ing letter to Professor Poulton is quoted from the Proc. 
Ent. Soc, June 5, 1912, p. Ixxxv : "I have already told 
you that I have seen male hobleyi flirting with female 
terra and vice versa, both hovering flutteringly in the 
air. Since then I have seen a male obscura paying court 
to a female terra in the same way. This makes the 
observations complete. ... So far I have not succeeded 
in getting eggs, though I have kept four females full 
of ova : three have died without result, the fourth I 
have had for a week and it is still living, though it has 
hardly any wings left." 

However, prolonged observation in the forests at 
. 1 Trans. Ent. Soc, 1911, pp. 57-9. 



260 PSEUDACRAEA EURYTUS 

length met with success, as told in a letter dated June 
16th (and partially printed in the Proc. Ent. Soc, 1912, 
p. cxv) : 

" I feel I can almost say, as did Charles Kingsley, 
' At last ! ' To-day (Sunday) being a sunny morning 
after many wet mornings, I went butterflying. I saw 
a few freshly emerged Pseudacraeas, and, just as I was 
coming away, saw a beautiful obscura, whose very large 
pale areas indicated more than a touch of the female 
hohleyi. It was fluttering about from bush to bush, 
and was too shy to let me get near to catch it. At last 
it settled, and hung from the underside of a leaf, and I 
was able to see it had a fairly distinct basal triangle 
(indicating admixture with the form hohleyi). It remained 
motionless a few seconds, and though that attitude is 
exceptional for Pseudacraea (they always rest on the 
upper side of a leaf with wings usually expanded) it never 
struck me what was up. I tried to catch it, but it flew 
off before I got within striking distance. It then occurred 
to me to look at the leaf, and to my inexpressible joy 
and excitement, there was a freshly laid egg on the middle 
of the under surface, still moist with the secretion which 
fastened it to the leaf. So, if this egg produces a terra 
(and the chances are in favour of this, as terra is much 
the commonest here), you will have the proof you so 
ardently desire, seeing that the parent was a mixture 
of hohleyi and ohscura ! Anyhow, now that I know and 
have found the food plant, I may have better luck in 
getting a captive Pseudacraea to lay. There is just time 
for the egg, larva, and pupa to develop before the con- 
gress at Oxford is over, so that, should the offspring be 
terra or hohleyi I will let you know. As of course there will 
be no time to write, I will cable just the one word, either 
terra or hohleyi. If it is ohscura I will not cable, but 
will, of course, write. I feel that it will be such a splendid 
opportunity for making this result known when you 



PROOF BY BREEDING 261 

will be showing the Pseudacraeas with special intent to 
prove their conspecificity by the intermediate forms." 

This egg, whose development is fully recorded else- 
where, ^ with descriptions of the larva at different stages 
(which I dubbed " Toby," feeling that he was important 
enough to deserve a name !) and of the pupa, eventually, 
on August 16th, became a butterfly of the form terra, 
somewhat transitional to obscura. Thus was obtained the 
first proof by breeding that the forms of eurytus known 
as tirikensis, hobleyi, terra and obscura are conspecific. 
The cable bearing the single word " terra,^^ probably the 
first cable ever sent about a butterfly only, did not reach 
Oxford until after the conclusion of the Entomological 
Congress, but Professor Poulton announced the result 
in the letter to Nature (September 12, 1912, p. 36), which 
has been already partially quoted. 

A letter that I received from him may be quoted here. 

August 19, 1912. — " I must write at once now that 
the great cable has come to-day. I will send a letter 
to Nature next week, so that you may get the credit at 
once of this most important discovery. . . . 

"It is splendid to have this great disturbing question 
settled at last. Your work is a splendid help towards 
confirming the Darwinian theory of mimicry. ... I 
must now conclude, but cannot do so without again con- 
gratulating you on this great success. I have longed 
for this to be done for two or three years, and have tried 
my best to induce friends to do it. I even tried to persuade 
Millar to journey from Durban on purpose to do it ! 
It is a splendid thing to have accomplished ; quite side 
by side with Marshall's breeding of the seasonal forms 
of Precis.^ . . . 

" P.S. — After your cable I imitated your example 
and have just had a sleepless night ! But it's only 

1 Trans. Ent. Soc, 1912, pp. 706-11. 

2 Ibid., 1902, pp. 417-58, 



262 PSEUDACRAEA EURYTUS 

natural, and to be expected after such exciting intelli- 
gence." 

Again, on October 26, 1912, Professor Poulton wrote : 
** I am glad that you are realizing the great importance 
of this material as a test for Natural Selection against 
Mutation. It seems almost too good to be true. ..." 
On November 22, 1912, he again wrote : 
"I do not doubt that imitator in Natal is just as 
successful as eurytus on the West Coast. Probably 
nowhere in Africa are Pseudacraeas quite as successful 
as they are in Uganda. But on the West Coast they 
are very polymorphic, in Natal monomorphic, yet both 
about equally successful. I take it that any variety in 
Natal that might lead on to a new form is at once exter- 
minated because there is only one Planema there, namely 
aganice, but on the West Coast there are many models, 
and any variety leading to one of them causes the varia- 
tion to fall into the surviving percentage. If that model 
disappeared the form would then drop out. We get all 
this happening round Entebbe according as the models 
change or disappear " (e.g. the change in hohleyi from white 
banded to brown banded hind wing, and of the female 
from tirikensis to poggeoides in different proportions in 
different parts of Uganda). " Only to-day I saw the male 
hohleyi from Neave's Western Uganda series with a brown 
bar crossing the hind wing, and in the same lot was the 
Planema, a form of macarista with a similar male." (This 
form is known as pseudeuryta, and has been already 
alluded to.) 

"I do not believe that any of these mimics depend 
for their existence on the model. The pattern depends 
for its existence on the model, but not the species which 
produces the j)attern. That is to say, Pseudacraea 
eurytus is a species which could stand by itself, and indeed 
does so on certain islands where the protection afforded 
by Planema models is non-existent, but the form 



FAMILIES REARED 263 

in which it appears is influenced by the varying pro- 
portions of these models. Reasons have already been 
given for regarding eurytus as a species at least partially 
protected." 

On November 23, 1912, Professor Poulton writes 
again : 

" The non-variation of imitator seems to me quite 
explicable by selection, for in its locality there is only 
one Planema. Rogersi may be looked upon as the con- 
necting link between Uganda and Natal, and I have not 
the least doubt that there are plenty of Pseudacraeas in 
British East Africa and further south, but they are mis- 
taken for Planema by collectors. ... I have no doubt 
you are right about hobleyi being the most distinct form ; 
that it should keep its sexual dimorphism so clearly is 
further evidence of this, and I should suspect it does 
follow the Mendelian relationship to one or both of the 
others. It would be very interesting if this could be 
tested : the main reason against it is the very great 
abundance of intermediates. For this reason I should 
very much doubt a Mendelian relationship between 
terra and obscura." 

Since " Toby " was reared I have been fortunate enough 
to obtain eggs from females kept in captivity. They 
were put with branches of the Chrysophyllum into a large 
wooden box whose sides and top had been partially 
replaced by mosquito net. The box was placed on tins 
standing in water in a large basin which stood on a fallen 
tree trunk in a small open place where gleams of sun- 
shine could penetrate into the cage. I had no success 
unless the butterfly was kept in the forest, since the 
species seems to be easily killed by the less humid atmo- 
sphere outside the forest, and the greater heat. Several 
small families were reared from known mothers, and 
may be seen with the parents in the Hope collection at 
Oxford. 



264 



PSEUDACRAEA EURYTUS 



Family. 


9 Parent. 


Offspring. 


1 


obscura -tirikensis 


1 . ? terra-tirikensis 

2. ? obscura-tirikensis 

3. ? terra-tirikensis 


2 


obscura 


1. (J obscura-terra 


3 


obscura-tirikensis 


1. $ terra-tirikensis 

2. ? terra-obscura 

3. ? terra-tirikensis 

4. ? terra-obscura 

5. c? obscura-terra 

6. ? o6scMro-<erra 

7. c? obscura-tcrra 


4 


tirikensis 


1. ? tirikensis 

2. (J }iobleyi-terra-obsc\ 

3. $ obscura-tirikensis 


5 


terra 


1. cj terra-hobleyi 


6 


tirikensis 


1. $ tirikensis 

2. cj hobleyi 

3. ? tirikensis 

4. 9 tirikensis 

5. ? tirikensis 

6. $ tirikensis 


7 


tirikensis 


1. (J obscura-terra 

2. cj obscura-terra 

3. (? hobleyi 

4. $ obscura 

5. (? obscura-terra 

6. c? obscura-terra 

7. (^ hobleyi 

8. 9 obscura 


8 


terra-tirikensia 


1. (? terra-hobleyi 



It seems as if the forms hobleyi and tirikensis were 
predominant over the other two, for although ^ena and 
obscura tainted with hobleyi or tirikensis abound (as shown 
by the umbre triangle at the base of the hind wing), yet 
I have never seen a specimen that could be described 
as hobleyi tainted with ^erra or obscura. So far, <ena 
or obscura untainted with hobleyi or tirikensis have not 
been bred from tirikensis parent, and one of the most 
abundant intermediate forms is ferra with more or less 



MODELS, MIMICS AND INTERMEDIATES 265 



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266 PSEUDACRAEA EURYTUS 

of the basal umbre indicating influence by hohleyi or its 
female tirikensis. It would seem as if hohleyi and tiri- 
Tcensis are the strongest and most stable forms, influencing 
the other two. 

These abundant forms of Pseudacraea eurytus that 
have been captured on the islands of Lake Victoria have 
a very important bearing on the explanation of mimicry 
by Natural Selection. As is abundantly evident from 
letters quoted, Professor Poulton believes that here is 
strong evidence of the efficacy of Natural Selection in 
at least keeping the mimics up to the mark. When models 
are scarce no one form of Pseudacraea has any particular 
survival value over another, and all kinds of non-mimetic 
transitional forms are preserved which, when the models 
are superabundant, are presumably destroyed by enemies 
so that they do not appear in collections. 

It would be of the very greatest interest at the present 
time to obtain offspring from the mimetic forms on the 
mainland and ascertain whether they will produce transi- 
tional offspring. Indeed, we know that they do produce 
a certain proportion of these, for two examples have 
been captured at Entebbe and have been alluded to 
before. 

The table on p. 265 shows by comparison the difference 
between collections made without prejudice at localities 
where Planema outnumbers Pseudacraea, and where the 
latter are predominant. 

The chart on p. 267 shows very graphically how the 
figures vary and the manner in which the numbers of 
Planemas and of intermediate Pseudacraeas vary inversely. 

A most remarkable thing is the complete change in 
the proportion of Planema to Pseudacraea on Kome 
Island and its near neighbours to the west in the period 
between 1914 and the end of 1918 and commencement 
of 1919. When I was on Kome for several months in 
1914, Planemas far outnumbered Pseudacraeas, which 



MODELS, MIMICS AND INTERMEDIATES 267 

showed very little variation, as may be seen from the 
table. 

But to my great astonishment, when I returned to 
the same islands after the war, the situation had been 
completely reversed, and the Pseudacraeas, which showed 
much variation, greatly outnumbered the Planemas 
(see table, p. 265). It must be supposed that the 
Planemas had been found at the summit of a wave of 
prosperity in 1914, but that their enemies (possibly 
parasites) had increased so greatly that they in turn 
reached the summit of a wave while the Planemas fell 



Proportion of 
Planemas in file 
tot^l captures 
of Butterflies. 


90 

80 
70 


Entebbe 
1909 


bamba 1^ 
1911 


Bugallals 
191 i • 13 


Kome group 
1914 


Kakindu. 
1915 


Komegroup 

1918- 19 


Sundri/oim 
Islesi9i8-i9 


q 






1 


\ 




P 

1 
1 

1 
1 

1 




o>60 
^50 
<{;40 




\ 


; 


1 




\ 1 




Proporhon of 
intermediate 
to total number 
of Pseudacraeas 


50 
20 
10 


y 


^-. 


^ 




/ 


^ 


• 



into a trough. This would be analogous to what is known 
to happen in England in the case of the Hop Aphis and 
the Ladybirds which feed upon them, each in turn 
fluctuating in number. 

It is most interesting to note how the Pseudacraeas 
changed in constancy, the intermediate forms having 
been apparently destroyed while the models exercised 
their protection to the mimetic forms in 1914, but 
having an equal chance of survival in 1918-19 when 
the protection of the models was in abeyance. Young 
birds in 1914 had a different lesson to learn from 



268 PSEUDACRAEA EURYTUS 

those of 1918-19 ; and also those that had learnt their 
lesson in 1914 must be supposed to have unlearnt it in 
1918, when the models which they had known to be 
distasteful were no longer to be seen. If this be so, then 
it must be further supposed that birds need to refresh 
their memories at intervals during adult life. 

These numerous and beautifully graded transitional 
forms of one species are quite consistent with the explan- 
ation of mimicry being produced and maintained by 
the continuous operation of Natural Selection upon small 
variations. 

But at first sight they do not seem to be at all in con- 
formity with the theory of the production of mimics by 
Mutations — that is, sudden large variations which appear 
complete all at once and never revert to the form of the 
parent. Indeed, the writings of such an exponent of 
the Mutation theory as Professor Punnett seem at first 
sight to support this argument, that the intermediates 
are a difficulty in the way of the Mutationist. 

Thus, in the 5th edition of Mendelism, 1919, he dis- 
cusses two forms of an interesting species of Euralia, a 
Nymphaline of which the form wahlbergi mimics Amauris 
niavius dominicanus, and the form mima mimics Amauris 
echeria. On p. 177 Professor Punnett says: "According 
to Mendelian views, on the other hand, the dominicanus 
pattern arose suddenly from the echeria pattern (or vice 
versa), and similarly wahlbergi arose suddenly from mima. 
. . . On the modern Darwinian view natural selection 
gradually shapes mima into the wahlbergi form owing to 
the presence of dominicanus ; on the Mendelian view 
natural selection merely conserves the wahlbergi form 
when once it has arisen. Now this case of mimicry is 
one of especial interest, because we have experimental 
evidence that the relation between mima and wahlbergi 
is a simple Mendelian one, mima here being the dominant 
and wahlbergi the recessive form. The two have been 



INTERMEDIATES AND MUTATION THEORY 2G9 

proved to occur in families bred from the same female 
without the occurrence of any intermediates, and the 
fact that the two segregate cleanly is strong evidence in 
favour of the Mendelian view." 

In the case of the theoretical origin of wahlbergi from 
mima the change in pattern is a large one, and it may 
well be asked what are the chances against the proba- 
bility of the dominicanus-wahlbergi pattern arising sud- 
denly, complete, in two cases, from the very different 
echeria-mima pattern, and in such a way that at one 
step the new pattern is the same in the two new butter- 
flies and differs in the same way from the parent pattern ! 

Moreover, the possibility of the same large variation 
suddenly occurring in these different butterflies is rendered 
still more remote by the fact that while mima and wahlbergi 
are forms of one species, echeria and dominicanus are 
different species of one genus and by no means closely 
related within that genus. The two examples given are 
therefore not analogous. 

Again, in Bedrock, vol. ii. Professor Punnett discusses 
the polymorphic forms of the mimetic oriental " swallow- 
tail " butterfly Papilio polytes. He says : " Mr. J. C. F. 
Fryer has recently succeeded in carrying out an elaborate 
series of breeding experiments with this species and has 
shown that any form of female can produce any other 
form provided that she mates with an appropriate male, 
while in certain cases all three forms may appear in the 
same brood. Even in such a case all the three forms 
are sharply cut and clear, there being a complete absence 
of intermediates or transitional forms." 

Incidentally it may be remarked in passing that had 
Mr. Fryer worked with the African Papilio dardanus 
there would not have been a complete absence of tran- 
sitional forms. 

At first sight the Mendelian argument seems to be that 
absence of intermediates is proof of origin by mutation. 



270 PSEUDACRAEA EURYTUS 

It would seem therefore that abundance of intermediates 
as in the case of the Pseudacraeas is in favour of the 
Darwinian explanation. But the Mendelian claims their 
presence also to be explicable by the theory of mutations. 
Thus in the same article in Bedrock Professor Punnett 
discusses the various offspring of a cross between a 
" Silky hen " and a " Brown Leghorn " cock which 
show grades of transition, and says : " Even if a completely 
grading series " can be put together, it does not follow 
" that the various forms have arisen through the accumu- 
lation of minute variations." The series intergrading 
between the two extremes of the cock and hen " can be 
expressed in terms of two Mendelian factors. . . . Thus 
an appearance of continuity in variation may be brought 
about by the interaction of a small number of definite 
factors upon one another." And in Mendelism, p. 162, 
Professor Punnett says: "Neither the existence of such 
a continuous series of intermediates, nor the fact that 
some of them may breed true to the intermediate con- 
dition, is incompatible with the Mendelian principle of 
segregation." 

In his book on Mimicry in Butterflies, he also says, on 
p. 129 : "As the result of modern experimental breeding 
work it is recognized that an intermediate form between 
two definite varieties may be so because it is heterozygous 
for a factor for which one variety is homozygous and 
which is lacking in the other — because it has received 
from only one parent what the two typical varieties 
receive from both parents or from neither. Its germ 
cells, however, are such as are produced by the two 
typical forms, and the intermediate cannot be regarded 
as a stage in the evolution of one variety from the 
other. ... It is quite possible that the new mimetic 
pattern appeared suddenly as a sport, and that the inter- 
mediates arose when the new form bred with that which 
was already in existence." 



INTERMEDIATES AND MUTATION THEORY 271 

The extraordinarily varied forms of P. dardanus, sub- 
species polytropJms, on the high Kikuyu escarpment 
(6,500-9,000 feet) in British East Africa do not support 
the view that the mimetic patterns arose suddenly and 
the intermediate forms from them by interbreeding. 
Many of these transitional forms are abundant on the 
escarpment, but are very rarely found elsewhere ; that 
is, they have a certain peculiar geographical distribution. 
" The Kikuyu escarpment is the only locality at present 
known where these transitional forms make up a large 
proportion of the females." ^ 

Such a distribution is far more consistent with the 
interpretation that these are an ancestral set of forms, 
such as may have existed before the different named 
forms became as distinct as they are to-day, which have 
been left isolated on a mountain ridge. 

One of the most varied of all these ancestral forms is 
trimeni, which is not considered to be an intermediate 
between two other forms of m-imetic females, but to show 
how the female first began to depart from the ancestral 
type like the male. That is to say, trimeni is at one end 
of the long series of female forms, and cannot be supposed 
to be a stage between two others. 

Thus it is seen that these intermediate forms are held 
by both Darwinian and Mendelian to support the respec- 
tive hypotheses of evolution, but the latter has perforce 
to fine down his " large " variations or " sports " to such 
a small size that they appear to be of the kind which 
the Darwinian recognizes as " small " variations upon 
which Natural Selection can, and apparently does, work. 

The Mutationist claims that if these differences are 
inherited according to Mendelian laws they must be 
of the nature of *' large " variations ; the Darwinian 
claims that they are the " small " variations which he 

* Poulton, " Mimicry, Mutation and Mendelism," Bedrock, vol. ii, 
p. 49. A plate in this article shows some of these Kikuyu forms. 



272 PSEUDACRAEA EURYTUS 

believes to be acted upon by Natural Selection, and 
adduces proof that they can be inherited ! 

One can quite appreciate the argument that the theo- 
retical origin of Euralia wahlbergi from a form of such 
different appearance as mima would be an example of 
origin by " Mutation " or *' Sport," but when it is neces- 
sary to fine down the " largeness " as in the intermediate 
fowls it becomes an apparent absurdity to allude to these 
differences as " large," that is, as " sports." It seems 
difficult to draw distinctions between the Mendelian's 
" Mutation," which is inherited by segregation of some 
very minutely differentiating " factor," and the Darwinian 
" small " variation, which can be inherited, but which 
the Mutationist calls a " fluctuation " and says is non- 
heritable, but if proved to be heritable claims as a 
"mutation" or "large variation." 

If segregation comes down to produce such minute 
differences, the term " large variation, mutation or 
sport " seems to be worn rather thin ! 

On this matter the work done by T. H. Morgan upon the 
colour of the eye in the fruit fly Drosophila has a bearing. 
The eye is normally red, but in the investigations upon 
the inheritance of the eye colour it was found that there 
were seven gradations between white and red, and further, 
one of the grades has seven modifying factors, each of 
which altera its intensity and gives rise to a secondary 
grade. Professor Jennings remarks that " by means 
of these graded changes one could obtain, by the 
mutationist 's own statement, the continuously graded 
results which selection actually gives. What more can 
the selectionist ask ? " ^ 

A case strictly analogous to the case of Ps. eurytus, 
with its abundance of insular variations in the absence 
of the models, is noted by Professor Poulton in his presi- 

^ See a summary of Jennings' papers by Professor Poulton in the 
Proceedings oj the Entomological Society oj London, 1917, pp. Ixxxv-lxxxix, 



INTERMEDIATES IN ABSENCE OF MODELS 273 

dential address to the Linnean Society in 1916. Dr. 
Lamborn bred Papilio dardanus on the west coast of 
Africa (South Nigeria), where the black and white form 
hippocoon is almost the only form known. This mimics 
the abundant Amauris niavius. Another form of dardanus 
female has been caught rarely all along the tropical west 
coast of Africa. This has a fore wing pattern approaching 
that of hippocoon, but with the bar between the subapical 
and inner marginal white areas very ill defined, and the 
hind wings are yellow instead of white. This rare form 
is known as dionysus, and there is no model for it in 
Nigeria. 

Lamborn bred from a hippocoon parent nine female 
forms like it, but also eight dionysus which has never 
been bred before. Now these dionysus are in a position 
similar to the Pseudacraeas which, in the absence of control 
by the models on the islands, are producing large numbers 
of transitional varieties, for no two of them are alike, 
and they present a beautifully graded series, from a fore 
wing pattern approaching that of hippocoon to a pattern 
closely approaching that of the male. The nine hippocoon 
sisters, however, mimicking the abundant Amauris, present 
a very close resemblance to each other and to the hippocoon 
parent. 

It is noteworthy that in the case of both Papilio dardanus 
and Pseudacraea eurytus the variation in the absence 
of models is best shown in the shape, size, and sharpness 
of outline of a dark bar separating the paler portions 
of the fore wing into two main areas. 

We now come to discuss another point of great interest. 
If the collections of Pseudacraea eurytus from different 
islands in the lake, sometimes very close together, be 
compared, further evidence in favour of the maintenance 
of mimetic resemblance by Natural Selection is obtained. 

Although the islets of Kimmi and Ngamba are so 
very close to each other and Kome (see map), yet the 

19 



274 



PSEUDACRAEA EURYTUS 



predominant form of Psevdacraea is not the same on 
each island. 

At each locality the predominant Pseudacraea is that 
which mimics the species of Planema that is most 
numerous in that locality, and this is further borne out 
by the collection from Kakindu on the mainland to the 
west of the lake. 



Combina- 
tion. 


Models and Mimics. 


Kome, 
1914. 


Ngamba, 
1914. 


Kimmi, 
1914. 


Eakindu, 
1915. 


I 


PI. macarista J poggei (J ? . . 
Pa. eurytus hobleyi ^ 


56 

8 


23 
9 


15 
2 


10 

1 


II 


PI. macarista $ 

aganice montana $ 
alcinoe camerunica $ 

Ps. eurytus tirikensia ? 


}" 

8 


23 

7 


9 

2 


6 


III 


PI. epaea paragea (J ? 
Ps. eurytus obscura c? ? 


2 


2 


— 


16 


IV 


PI. tcllus eumelis c? ? 
P^. eurytus terra (J ? 


235 
35 


— 


— 


71 
12 



From the above table it is seen that while on Kome 
the model of type of colouring IV {Planema tellus) was 
most abundant, on Ngamba the species that predom- 
inated were of types I and II, and on each island the 
proportions of the forms of Pseudacraea are according 
to the prevailing type of models. At Kakindu, again, 
type IV predominated in the models, and all the Pseud- 
acraeas save one were of type IV. The islands mentioned 
are so close together that it would be absurd to attempt 
to explain the differences in the Pseudacraea fauna by 



VARIED FORMS ON DIFFERENT ISLES 275 

climatic conditions ; the factor that varies, however, is 
the proportion of species of Planema. The supposition 
is that on Ngamba a form of Pseudacraea that does not 
resemble male or female of Planema macarista has 
less chance of surviving birds' attacks than a form which 
is deceptively like macarista ; consequently the form terra, 
which is so common on Kome Isle only a few hundred 
yards away, is at a disadvantage on Ngamba. 

This explanation, of course, presupposes that the 
species of birds which are presumed to exercise selection 
do not fly across from Ngamba to Kome or vice versa 
(see map). Now, although Bee-eaters may constantly 
be seen crossing open water in flocks, I do not 
think that I have ever seen such birds as Flycatchers, 
which abound on the islands and, in some cases at least, 
only in the forest which is the haunt of Pseudacraeas, 
crossing from one island to another. I have even noticed 
that the very characteristic songs and call notes of species 
such as the " Kunguvu " (Tchitrea emini) and a pretty 
little black and white Platysteira (? jacksoni) varied on 
different islands. 

While on Bugalla in 1912-13, I became extremely 
familiar with the call of these abundant birds, and 
directly I visited the Kome group of isles in 1914 at 
once noted a difference — yet the difference was slight 
enough to make me feel certain that the species of 
bird was the same. This seems to show that at any 
rate on islands at this distance apart there is a tendency 
for geographical races to be perpetuated, but I have 
not been long enough among the islets of the Kome group 
to know if the song of the flycatchers of Ngamba differs 
from that of the same species on Kome. Yet, as has 
been shown in Chapter VI, many islands quite close 
together show distinct differences in their avian fauna. 



CHAPTER XII 

HYMENOPTERA 

Ants. 

The ant that most obtrusively calls for notice is the 
well known Dorylus or " Safari ant," known to the 
Baganda as " Ensanafu " and in Kiswahili called 
" Siafu." 1 

This totally blind reddish ant varies exceedingly in 
size, the largest individuals being half an inch long and 
several times larger than the smallest, but it is diificult 
to make out any difference in their functions. 

They live entirely by hunting live prey, and ov/ing 
to their incredible numbers must destroy very many 
of the creatures that are unable to escape them. They 
make temporary subterranean nests, which are easilyJ 
discovered on account of the piles of loose earth that] 
has been brought up from below grain by grain, and] 
the numerous large irregular holes leading down to the] 
burrows and chambers in which the queen lives and the] 
young are reared. The queen is a curious looking creature,! 
with abdomen much enlarged, as is the case with thej 
well known queen termite, but in the latter the 
distension is very much greater. 

Queen Dorylus are rare in museums, probably becausej 
of the courage that is required to dig one out of the nest 
among the hordes of ferociously biting workers ; a native 
once brought me two, but I should have liked to see 

1 Dorylus nigricans and glabratus. 
276 



ENSANAFU ANTS 277 

him getting them, from a safe distance ! The adult 
male has been elsewhere alluded to in connection with 
signs of the weather. The worker Dorylus are often 
seen travelling swiftly in a column several ants wide, 
in a very orderly manner : hence the name Safari ant. 
They prefer a sheltered route among and under leaves 
or dense grass, but where they must cross an open smooth 
area such as a well trodden path, they sometimes make 
a tunnel for at least part of the way beneath the surface, 
or a deep furrow. At other times, however, they protect 
the travellers by forming a line on each side of the track, 
the ants standing high on their legs with mandibles 
wide agape as if seeking for something to bite. These 
guardians are so intertwined that they make a living 
wall which often bridges right across the ceaseless stream 
hurrying below. If interfered with, or disturbed by 
the tramp of a foot shaking the ground, they break loose 
and run about with menacing jaws, but do not go far, 
and if nothing is met within a yard of the column 
the guardians return and re-form the protective wall. 
These columns of hurrying ants fill one with amazement 
on account of the immense numbers of individuals. 

The first one I saw was crossing a road close to my 
hut on the evening of July 18, 1910, and next morning 
the stream was still showing no signs of abating. It 
was about an inch wide, and 4-6 ants across. At noon 
the ants were still pouring across the road in the same 
direction, but by 5 p.m. those forming the protecting 
walls had moved, and by sunset they had all gone across : 
that is, for about twenty-four hours there had been a 
continual stream, for there is no reason to suppose that 
this column was exceptional, and had ceased to move 
when night fell. 

This column was apparently changing camp, for nearly 
every ant carried a naked white pupa, although it is a 
curious fact that not a single larva was seen in the pro- 



278 HYMENOPTERA 

cession. Indeed, it may here be said that I have never 
seen Dorylus carrying its larvae on safari, only the pupae ; 
nor does one ever see a queen travelling. Is it possible 
that a column such as is above described is analogous 
to a swarm of bees, but that instead of taking a queen 
with them the members of the swarm carry pupae, from 
one of which a queen will emerge when they have ex- 
cavated a new nest ? It is curious that where there are 
large and small ants there should not be some differen- 
tiation of function. Quite small individuals are seen 
struggling along carrying enormous pupae, while lusty 
fellows of the biggest size appear quite content whether 
they are carrying a small individual or one of their own bulk. 

Although, on the whole, the column is an orderly one, 
occasionally considerable confusion is caused by indi- 
viduals running back against the stream ; possibly they 
are "returning empty" ! If they are of very small size, 
they are often seen to be unable to make headway against 
the hurrying multitude, and unless they run quite at 
the edge are at length compelled to turn round and run 
with the rest. A very large individual, however, since 
it stands well above the small ones, can often run against 
the tide, for the small ones can run under it, between 
its legs. 

But every column of Ensanafu that one sees is not 
engaged in changing camp ; most often they are either 
going out to hunt, or returning laden with spoils. 

When they have reached the hunting ground the main 
column breaks up into minor streams, and the ants swarm 
over the ground, investigating every nook and cranny 
and climbing up bushes. 

If one is in the forest when they are hunting, one often 
first becomes aware of it by hearing a peculiar pattering 
noise, caused by the countless ants which have run up 
branches to the extreme tip, and finding no prey there 
drop off and fall on to the leaves below. 



ENSANAFU ANTS 279 

Their activities are also revealed by the great dis- 
turbance they cause among the countless spiders and 
insects of all kinds that have previously been concealed 
among the dead leaves and ground cover. Before one 
sees the hunters themselves one meets spiders, harvest- 
spiders (Phalangeridae), caterpillars and especially cock- 
roaches scurrying away in great excitement. As one 
draws nearer to the area being hunted over, one sees 
little masses of Dorylus ants busily engaged in cutting 
up some unfortunate insect that has failed to escape, 
and then, standing just outside the area and keeping 
careful watch around one's feet, one can see the hunters 
running about and going into every nook and 
cranny. 

A cockroach takes fright and rushes out from under 
some dead leaves, only to be seized by one or more ants 
and overpowered by superior numbers. Sometimes, on 
a sandy shore, where they have a chance of running away, 
the cockroaches forfeit their lives by losing all presence 
of mind and running wildly hither and thither, often 
tumbling head over heels in their frantic endeavours to 
escape, and so falling all the easier prey. 

Sometimes, however, certain spiders by moving 
cautiously first in one direction and then in another, 
and, as it were, feeling their way, manage to evade the 
awful fate of being eaten alive. 

It is an unpleasant sight when a huge caterpillar is 
seen writhing and twisting in the endeavour to free itself 
from the numerous ants which have firmly fixed their 
sharp jaws in its skin and will not leave go. 

Slugs of large size are cut up piecemeal, although some 
of the ants at least are overwhelmed and suffocated in 
the slime that is secreted more abundantly when the 
slug is attacked. 

A certain snail that was common on Damba Isle 
was able, as related in another chapter, to keep the ants 



280 HYMENOPTEUA 

at a distance by surrounding itself with bubbles of foam 
into which the ants could not penetrate. 

A medium sized Plant bug (Hemiptera) was once seen 
on a leaf of a bush over which Dorylus was swarming, 
and I was much interested to note that although ants 
would frequently seize hold of a limb or antenna of the 
bug they always let go again, and no harm was done to 
the bug. It is possible that its powerful odour may 
have been disagreeable to the ants. 

One night a large army of Ensanafu raided my grass 
hut on Bugalla Isle ; fortunately I was sleeping in a 
tent close by, and though a column ran through the 
tent they were only on the way to the hut, and I was 
not turned out. But a nestful of fledgling swallows in 
one corner of the hut was cut up and carried away piece- 
meal. 

One day at Jinja I heard pitiful squeakings coming 
from some long grass, and found a baby striped rat being 
attacked and in danger of a horrible fate ; needless to 
say he was freed, but very likely fell a victim subsequently. 

During the campaign in German East Africa I was 
twice turned out of the little tent in which I was sleeping 
on the ground by an invasion of Ensanafu, and had to 
bolt, and then, after picking off those ants which had 
already attached themselves to various parts of my 
person, make a dash for boots, and by frequent painful 
visits gradually withdraw the bedding and shake down 
elsewhere outside, while the ants proceeded along the 
line to some one else's tent, to my secret gratification, 
for no one likes to be the only one who is turned out in 
the night ! 

On Damba Isle in July 1911, I saw a very interesting 
thing while watching the unfortunate denizens of the 
shady forest being turned out by Dorylus. Cockroaches 
were scurrying about in all directions, and hovering 
over them, and occasionally darting down upon them, 



ENSANAFU AND STINK ANTS 281 

was a small, thin bodied, long legged insect whose appear- 
ance suggested a Syrphid fly, though one seemed to have 
a short ovipositor, which would imply that it was an 
" Ichneumon " fly. 

After watching for some time I suspected that the 
fly's object was to dart down and lay an egg upon a 
cockroach before it was cut up by the ants. Presumably 
the egg would thus be carried into the nest, where the 
larva would find food that it required, and possibly frag- 
ments of insects that had been brought in by the ants. 

Bates, in his Naturalist on the Amazons, describes 
something similar in the case of Stylogaster and the Eciton 
ant, which has habits analogous to those of Dorylus. 

In July 1914, I saw an interesting affair on Bulago 
Island. A small column of Ensanafu was hunting, and 
had discovered in a hollow, broken cane stem the nest of 
another ant, a large black species whose rotund abdomen 
is covered with golden pubescence. The rightful owners 
of the nest had found discretion the better part of valour, 
and were no longer attempting to resist the raiders, who 
had bitten through the stopper closing one end of the 
stem. Some, inside, brought up the grubs in the nest, 
which were at once seized by eager helpers outside, who 
usually fell to the ground with their burden in their 
excitement. It was a busy scene, and curiously reminded 
one of the unloading of a ship. 

Another abundant ant is the giant Paltothyreus tarsatus, 
known to natives as " Waka," and to Europeans as 
" Stink ant," owing to the appalling smell of bad eggs 
emitted by it when roughly handled. About an inch 
long, coal black in colour, this species is often seen singly 
slowly wandering about searching for food. It seems to 
live on animal food — small insects or bits of dead ones 
which it meets with on its wanderings — but is not active 
in its movements. If handled it can inflict a severe sting. 

The Waka nests underground, and in disused chambers 



282 HYMENOPTERA 

in the base of old termite hills : one such nest that I dug 
out was perceptible to the nose from some yards away. 
When the nest was broken open the ants and termites 
running about of course met, and the termite invariably 
seized hold of the ant. But the ant seemed to be too 
hard for the termite to make any impression on it, and 
if unable to free itself by struggling turned its abdomen 
forwards and deliberately stung the termite, which at 
once let go and seemed more or less paralysed. One ant 
was tackled successively by two termites, and accounted 
for each in turn, but it was never the aggressor, and 
seemed reluctant to sting until other methods failed to 
release it from the termite's grip. I have found a winged 
male of this ant in the stomach of a Bee-eater. 

Another large black ant that is often confused with 
Paltothyreus is Megaponera fmtens, though it is con- 
siderably smaller, has no odour, and is of very different 
habits. The name foetens should apply to Paltothyreus, 
with which this ant, called " Enkolokoto " by the natives, 
must have been confused when the name was given 
to it. 

I mention this ant because it is absent from the islands, 
nor have I met with it on the Uganda shores of the 
lake. 

I first saw it when on active service on the southern 
frontier of Uganda in 1914 (Kagera river), and subse- 
quently became very familiar with it in German East 
Africa. But the Kagera river, which forms the natural 
boundary to Uganda, also seems to act as a barrier 
to Megapo7iera in that part of the world, for though the 
ant is often seen on the south side of the river, it was 
apparently absent from the north side. I was informed 
by a missionary, however, that he knew it well further 
north in Uganda. 

Megaponera feeds on termites, and marches out in 
orderly bands of a hundred or more, and when inter- 




HOUSE ON BUGALLA, I912-I3. 
Barbed wire lightning conductor over supports on roof. 




INTERIOR OF BUGALLA HOUSE. 



To face p. 282. 



SUNDRY ANTS 288 

fered with produces a distinct stridulating or squeaking 
noise. These characteristics make it easy to recognize. 
Probably it is absent from the lake area because its 
favourite prey is not found there. This is a species of 
dark coloured termite which does not build hills, but 
lives in burrows underground, from the open mouths 
of which they come out in daylight to cut the segments 
of grass blades, which they then drag down and pre- 
sumably eat. 

The remarkable ant (Ecophylla smaragdina has already 
been alluded to on account of its being mimicked by a 
spider and a bug. It is not found by any means on all 
islands, but was common on the trees overhanging the 
" fly beach " on Damba. The nest is a globular shell 
formed by leaves attached together along their edges 
with silk spun, as H. N. Ridley first pointed out, by a 
larva held between the jaws of an ant for that especial 
purpose, and applied first to the edge of one leaf and 
then to another. It is an inoffensive species, its feeble 
mandibles being barely able to pierce one's skin, and 
being without a sting. 

On Damba they fed largely on the thousands of small 
" E'sami " lake flies (Chironomidae) which settle on the 
leaves, but also from secretions of Aphidae on the stems 
of the leaves. The island specimens were of a shining 
light brown colour and form a distinct race, known as 
longinoda. Some that I saw in Portuguese East Africa 
in 1918 were more of a greyish brown tint. 

Another ant that lives on leaves of trees is known 
to the Baganda as " Obusaji-saji," but unfortunately no 
specimens were obtained for identification. 

It was very abundant on Bugalla and Damba, but does 
not occur on many islands. It is a small, very active 
long legged black species, which makes a frail nest of 
some friable brown material on the backs of leaves or 
between two leaves, which thus adhere together. 



284 HYMENOPTERA 

If one is so unfortunate as to disturb these when pushing 
between leafy branches, great numbers of the little ants 
rush out, and, getting a firm grip with their man- 
dibles, inflict a sting which leaves a burning irritation 
for several hours. It is particularly unpleasant when 
they find their way down one's back or into one's hair ! 

The most noticeable wasps are species of the genus 
Belonogaster : large, dark, grey-brown insects with long 
pedicle to the abdomen, known as " E'numba " by the 
natives. Their nest is of papery substance, and formed 
of a single tier of cells supported from a slender stalk, 
with the open mouths downwards. It is attached to 
the under side of an overhanging rock, or to the eaves 
of a house, and in a favourite site numbers of nests are 
seen close together. 

Natives are very much afraid of the sting of these 
wasps, which is certainly extremely painful, and do not 
like going near their nesting places. It must be acknow- 
ledged that there is reason for this, for sometimes a 
wasp will fly ofE the nest and viciously sting any one 
who it thinks has come too close, returning immedi- 
ately to the nest. I noticed, however, that if one allows 
a nest to grow up in a position constantly approached 
or passed by, the wasps become accustomed to people, 
and are inofifensive as a general rule. 

I allowed several nests to be built from the underside 
of the ridge of my tent, and the colonies grew to a large 
size without any sign of aggressiveness on the part of 
the wasps. But one day an officious individual, perhaps 
a freshly hatched and inexperienced one who had not 
been taught properly, flew off at me when I came into 
the tent and inflicted a vicious sting. This sealed the 
death-warrant, and all the nests were destroyed. 

The grubs in their cells hang mouth downwards, the 
anterior end of the body protruding slightly. They are 
watched over by certain individuals who act as nurses, 



BELONOGASTER WASPS 285 

while others go out hunting for the smooth caterpillars 
wherewith to feed them. 

A wasp having found a caterpillar pounces on it and 
stings it, and at once begins to pulp it with its large 
mandibles, beginning at one end and passing systemati- 
cally along the whole body. Finally, the mangled remains 
are rolled up into a pellet about the size of a pea, with 
which the successful hunter flies back to the nest. In 
one case that was observed two wasps were on the nest 
when the hunter (A) returned with a mashed-up insect 
in her mandibles. This she gave to B, who appeared to 
mince it up further and then shared it with C, each 
going to one of the larger larvae in the cells and holding 
the mass to its mouth. The larvae could be seen eating 
it. A afterwards went round and fed the larvae with 
fluid regurgitated : this process was accompanied by a 
kind of violent shuddering motion. I could see the 
drop of fluid appearing between the wasp's mandibles, 
to be slowly sucked up by the larva. 

Caterpillars are not the only prey of Belonogaster, 
for one frequently sees them capturing and pulping 
small brown Acraea butterflies, which is of interest 
when considering the enemies of protected insects. The 
Belonogaster itself may be considered a typical pro- 
tected insect, but I have found it in the stomach of a 
Bee-eater {Merops superciliosus). This subject is discussed 
elsewhere. 

Belonogaster has all the characteristics of a protected 
species, and serves as a model for a most interesting 
Neuropterous insect, Mantispa, which has been elsewhere 
described. 

Although it is not considered too formidable by the 
Bee-eater, which seems to be specially adapted to feed 
on stinging insects, there are probably few other birds, 
and certainly no mammals, that would dare to catch 
it, so that its enemies must be mainly other insects. 



286 HYMENOPTERA 

There are often to be seen in empty cells of the nest the . 
pupa cases of flies, one to a cell, probably Tachinidae, 
but I have not actually seen a fly depositing its egg on 
the wasp larva. These wasps belong to the Diploptera, 
or true wasps, whose wings are doubled up longi- 
tudinally when not in use, giving them a very narrow 
appearance. 

In the group of wasp-like insects now to be discussed, 
known as the Fossores, the wings are not folded. While 
some of them, such as Bembex, have a certain resemblance 
to a true wasp, most of them are readily distinguished. 

The group is remarkable from the habits whence the 
name Fossores, which means " diggers," is derived ; 
they are also called " Sand wasps." The wasp Belonogaster 
has been described above as feeding its young on insects 
which it has first killed and pulped. It is obvious that 
meat of such kind must be troublesome to prepare, and 
must be supplied fresh at frequent intervals. 

Some other wasps, which are of solitary habits (Odynerus, 
etc.), do not pulp the prey, but store them up whole in 
their burrow. But if one examines the store that has 
been laid up for the larva to feed upon, one finds that 
in the case of small geometrid caterpillars, some of them 
shrivel and dry up, and are not in very good condition to 
form food. 

One family of fossors, the Bembecidae, has slightly 
improved upon this method. They feed their larvae 
almost entirely upon whole flies, which they do not 
kill, but sting so that they remain alive and juicy but 
cannot move, since the central nervous system has been 
paralysed ; probably, therefore, they are insensitive as 
well. Regular supplies of these paralysed flies are taken 
down into the burrow by the mother Bembex. 

A further step in the saving of trouble is exemplified 
by other fossors of the families Sphegidae and Pompilidae. 
These lay up in a burrow a store of paralysed insects 



FOSSORS 287 

sufficient to feed one grub for the whole period of its 
growth. Having stocked the burrow, the mother lays 
an egg, affixing it to one of the living but helpless prey, 
and having sealed up the burrow for good and all, she 
goes off to make another. Sometimes this process in- 
volves very heavy labour, for the inert grasshopper, 
caterpillar or spider has to be taken to the burrow. 
Usually it is too heavy to be carried in flight ; some- 
times it can be carried walking, but often it has to be 
dragged along the ground. In the latter case the fossor 
first finds and stings the prey, and then excavates the 
burrow in a suitable spot in the neighbourhood ; but if 
she can carry her prey the burrow is excavated first and 
the prey carried back to it, gripped by the mandibles 
and carried between the legs. It is wonderful with what 
accuracy the mother will find her way over sticks, stones, 
bare patches of sand, or through thick grass, until the 
burrow is reached ; sometimes she travels backwards 
with her load ! 

It is an obvious saving of this labour to find the prey 
first, and then excavate the burrow where it lies. 

Another family, however, the Scoliidae, has economized 
labour even further. The larvae of these fossors feed 
upon the subterranean larvae of large Lamellicorn beetles. 
The mother burrows down to them and merely lays her 
egg upon them in situ, presumably stinging them first 
to render them inert, as is the custom in the Fossores. 

Lastly, there are the peculiar Mutillidae, whose wingless 
females, as they run swiftly over the ground, look like 
brightly coloured ants. These are mainly parasitic upon 
other Hymenoptera, and do not burrow, but pierce through 
the walls of the nest and lay their egg upon the larva 
inside, just as the typically parasitic " Ichneumon " fly 
lays its egg upon a caterpillar. Thus one can trace all 
stages between the somewhat crude method of the 
Belonogaster wasp down to the labour saving parasitism 



288 HYMENOPTERA 

of the Mutilla and the well known " Ichneumon " fly, 
parasites of caterpillars. 

It may be remarked here that " parasite " hardly 
seems the correct term for an Ichneumon larva, whose 
activities necessarily result in the death of its host, which 
is devoured as completely as an antelope is by a lion. 

The only difference is that at first the young Ichneumon 
larva feeds only upon the juices of its prey, and the 
essential tissues are not devoured until the larva is full 
grown, when it has nothing to fear in the death of its 
unwilling host. 

It does occasionally happen, however, if the dispro- 
portion in size is great between the host and the parasite, 
or if the number of parasites is very small, that the host 
is not killed. I once reared an Arctiid moth and a single 
parasitic Tachinid fly from the same caterpillar ! 

The habits of Bembecidae are, like those of other fossors, 
of absorbing interest. As has been pointed out, these 
feed their larvae on flies, ^ but they do not lay up one store 
for good and all as do the Sphegidae and Pompilidae. 
Perhaps the reason is that the flies, not being large-bodied, 
fleshy insects, might dry up before the Bembex larva 
had eaten them all. So the mother attends to her larva, 
bringing to it freshly stung flies at frequent intervals. 

Since this necessitates constant work opening and 
closing the burrow, it is dug in localities where the 
soil is very loose and light, such as a sandy shore on the 
lake, and I have found thriving colonies of Bembex in 
such situations. 

The first that I met with was on a dazzlingly white 
beach of fine sand on the south coast of Nsadzi Island, 
in March 1911, when I found numbers of B. forcipata 
flying about over the hot sand, and busily excavating 
their burrows, and spent many hours watching them, 

^ Occasionally on other insects. I have watched one catch a " Skipper" 
butterfly. See Proc. Ent. Soc, 1917, p. xli. 



BEMBEX 289 

for I soon saw that they were catching Tse-tse fly. 
A Bembex would alight on the sand at a spot which 
she evidently knew, although it was indistinguishable 
from the surrounding bare area, and commence to dig 
away the loose sand with her powerful toothed fore limbs, 
specially adapted for this work by a fringe of stiff hairs. 
So rapidly does she work that the sand is thrown behind 
her in a continuous stream, passing underneath her body 
and falling a couple of inches behind. 

Without a pause she persists, and soon lays bare the 
mouth of a pre-existing tunnel, at the bottom of which 
lies her grub, hungrily devouring flies. As she works 
in the loose sand it constantly trickles down from above, 
but she removes it at such speed that it is thrown out 
faster than it falls, and presently the burrow is clear and 
she disappears from sight into it. 

Sometimes she throws up behind her enough sand to 
block the entrance ; if she does this she usually remains 
below for some time, but what she does down there I 
know not. 

Presently up she comes, and, if she is careful, turns 
away from the mouth of the burrow and throws enough 
sand back into it to block the entrance. The reason for 
this will be given later. 

But quite often the careless worker flies away without 
closing the burrow, leaving the helpless grub at the mercy 
of any marauder that discovers the opening. 

Now the busy mother has to seek food for her young, 
and she flies round and round me as I sit on the sand, 
apparently looking for a nice fat Tse-tse fly full of blood ! 
Naturally she finds none, and has to take the next best, 
but searches very carefully, coming within an inch of 
my face and under the brim of my hat. Sometimes a 
Tse-tse that has been sitting on my clothes takes alarm 
and darts away, but not quickly enough to escape its 
enemy, who pounces on it in a flash, 

20 



290 HYMENOPTERA 

There is a shrill buzz, like a scream, from the fly as 
it is caught and stung, and then the Bembex is seen to 
be holding the fly closely to her abdomen between the 
thighs of her hind legs, and darts away to her burrow. 

Sometimes the Bembex pounces on a fly as it sits on 
my clothes, and I am able actually to see her sting it. 

Arriving at her burrow, Bembex alights at the exact 
spot, and without a moment's hesitation, still holding 
her prey between her legs, opens up the burrow and 
passes in. 

Almost immediately she emerges again and repeats 
the chase. On March 13th I thus watched one worker 
for three and a quarter hours, during which she caught 
twenty-nine Tse-tse and two other flies. The last four 
Tse-tse had been caught and carried into the burrow in 
five minutes. After this she finally closed the burrow 
and flew away, and I, with great difficulty in the loose 
sand, found the chamber at the end of the burrow and 
took out all the flies that had been collected, and the 
legless white grub, full grown. 

There were thirty-one Tse-tse flies and one other fly. 
About half a dozen of them were dried and some partially 
eaten. Twenty-one were males and ten females, eight 
of which were fat ones containing a larva ; this is a very 
high percentage of pregnant flies, for out of ninety-six 
female flies that had been caught by my boys that 
morning only 22 per cent, contained large larvae. 
So that the Bembex had definitely selected the fattest 
flies she could find in default of full fed individuals, which 
are heavier on the wing and easier to catch. 

Another specimen was seen to catch six Tse-tse and 
several other flies in an hour ; if, after close examination, 
8he found no suitable Tse-tse on me, she would fly away 
and return with other flies, though once she came with 
a Tse-tse caught elsewhere. 

The burrow of another that was dug up, about eight 



BEMBEX 291 

inches deep, contained a nearly full grown larva and 
twenty freshly caught flies, one of which was as large 
as a " blue-bottle," but the rest were all about the size 
of the common house fly, and appeared to be of several 
species — three of one species, nine of another, one of 
another, two of another, one of another, and three of 
another. 

It is a curious fact that the mother does not know 
when to cease provisioning the burrow, and gives her- 
self much unnecessary labour. Thus, in the first case 
described above, the larva was full grown and com- 
menced spinning its pear shaped cocoon at once. On 
another occasion I found that the Bembex had taken down 
flies to a larva that had already begun to spin its oval 
cocoon ! This is formed of silk, with grains of sand 
attached on the outer side, and measures about an inch 
in length. 

The mother Bemhex appears to pass the night in the 
burrow underground, for quite often, if one visits the 
colony early in the morning, a Bembex will suddenly 
emerge from the ground at a spot where the soil has not 
yet been disturbed that morning ; and also late in the 
evening they may be seen going down into the burrows 
and closing them behind them. The male spends an 
idle life basking on the hot sand or darting about in chase 
of the females, or sipping honey from neighbouring flower 
heads. 

The Bembex is a most delightful insect to watch, as 
she works at such high pressure, and so efficiently and 
quietly. 

She has her enemies, for wherever a colony is found 
there can be seen numbers of little brown insignificant 
flies, by name Idia, who await a chance to go down the 
burrow and deposit their own eggs on the flies laid up 
as store by the Bembex for her own offspring. 

As was pointed out, the Bembex may close her burrow 



292 HYMENOPTERA 

when she leaves it. The moment she has gone, up hurries 
one of the Idia flies and attempts to get through the 
barrier. Sitting ahnost upright on the end of the abdo- 
men, the little fly throws the sand forwards with quick 
movements of its legs, as if trying to burrow backwards 
through the barrier. But I have never seen one accom- 
plish more than making a slight dimple in the loose sand. 
But quite often the careless Bembex has gone away leaving 
the burrow open, and then the Idia has its chance. It 
hurries up with such eagerness to get down the burrow 
that it may be seen literally to tumble head over heels 
as it scrambles down. There is need for hurry, for how 
can it tell when the rightful owner will come back, and 
then it may meet with very rough treatment ! But as 
a matter of fact I have never seen Bemhex take any 
notice of the mean little intruder, though it may some- 
times actually be met at the mouth of the hole by the 
returning huntress. Yet sometimes it does fall a victim 
to the sharp sting, for among flies dug up from a burrow 
I have found specimens of Idia. 

Small pink dipterous larvae that are found in the 
burrows are probably Idia, though I was unsuccess- 
ful in rearing them. It is, of course, possible that 
they are not strictly enemies of Bemhex, even in an 
indirect manner, by devouring the larva's food ; they 
may merely feed on debris of legs and portions of bodies 
left by the more fastidious Bembex larva. 

Every colony of Bembex, of those species that I have 
seen, has had these little brown flies in attendance. Some 
were sent to the British Museum, and I was informed 
that the species was a new one, and this habit had not 
previously been recorded for the genus. 

The first Bembex that I ever saw at work was B. cap- 
ensis, which I found at Jinja in 1910. One was seen 
going into the burrow carrying a full fed Tse-tse, whose 
shining red, bloated abdomen full of blood was quite 




BACK OF HOUSE ON KOME ISLE, I9I4. 




FRONT OF KOME HOUSE. 



To face p. 292, 



BEMBEX 293 

unmistakable. Another burrow that was opened up 
was found to contain the remains of several small flies 
and of the Tabanid Chrysops brucei, besides two Tahanus 
thoracinus. The fact that Bembecidae prey upon Tabanidae 
is well known, but not, I think, that they prey upon 
Glossina, the Tse-tse fly. 

In March 1912, I saw the following curious incident 
on Bugalla Isle, where I had found a colony of Bembex 
ugandensis. One was seen to come out of her burrow, 
and soon returned with a small fly, went down, quickly 
came out and flew away, leaving the burrow open. 

There now appeared on the scene a medium sized 
fossor of quite a different type, with the black and orange 
" Lycoid " colouring. To my great surprise the stranger, 
after hunting about, found the burrow and went straight 
down ! Then she came out again and stood waiting at 
the mouth on the heap of loose sand, but soon went in 
again and stood with her head blocking up the entrance. 

The Bembex now came back carrying a fly of some 
kind, and attempted to go down the burrow, but on 
meeting the intruder flew off in a great fluster, dropping 
her prey. She soon came back, tried again, and again 
flew off, nonplussed. The third time she managed to 
get in, and I listened for the sound of an underground 
battle, but heard nothing. 

However, in a few seconds the stranger came out, 
not at all hurriedly, and flew away, but soon came back 
and went in again while the Bembex was still there, 
then came out again and stood at the mouth. I then 
incautiously frightened it away by moving. 

The Bembex now came out and flew away, and the 
intruder came back and stood inside the burrow again 
with its head at the entrance. After a while it flew 
away, but again came back and stood on the heap of 
loose sand outside the entrance, then buzzed round for 
a while and finally flew away. 



294 HYMENOPTERA 

I tried to dig up the contents of the burrow, but failed, 
and am at a loss to know what is the explanation of the 
intrusion. Unfortunately the Lycoid fossor was not 
caught for identification. 

Another family of Fossores is the Sphegidae, which 
contains insects of very varied size and habits, although 
they all agree in storing up paralysed insects or spiders 
for their young. The species of prey chosen by Sphegids 
differ greatly ; some choose spiders, many more grass- 
hoppers or crickets, and many others the smooth bodied 
caterpillars of Noctuid or Geometrid moths, but never 
hairy caterpillars such as those of Arctiidae or Lymantridae, 
though I have seen one species taking a pilose Lycaenid 
caterpillar into its burrow. If the species selected is of 
small size, a number must be collected, but very often 
a single individual furnishes all the food that a Sphegid 
larva requires. 

Although they all belong to the natural group Fossores, 
the Sphegidae do not all dig in the ground. 

A dead bough that contained a nest of a large Carpenter 
bee was also used by a large black Sphegid for its brood. 
A tunnel about half an inch in diameter had been exca- 
vated, and the mouth was stopped up by little pieces 
of wood and lichen. It penetrated perpendicularly into 
the wood for about an inch and then turned sharply to 
the right and ran longitudinally about four inches. At 
the end was a collection of the remains of some half- 
dozen small Locustidae, and a cocoon about an inch and 
a half long, formed of an outer silky and an inner papery 
layer. Inside the cocoon was the larva, and six small 
larvae, probably Diptera, which were presumably indirect 
parasites like Idia. Beyond the cocoon the passage was 
directed towards the centre of the bough, then turned 
to the left for two inches, and eventually opened to the 
exterior below the original opening. This second orifice 
was not stoppered. It is much to be regretted that 



SPHEGIDAE 295 

the species was not identified, since this method of nesting 
is very unusual for a fossor. 

Another very unusual nesting place was found to be 
used by a specimen of Sphex (Isodonta) pelopaeiformis. 
This was in the open end of the hollow stem of a broken 
reed. The Sphex was seen going there carrying a small 
piece of wood, and I found she had finished provisioning 
her nest and was stopping the hole at the end of the stem. 
There were two collections of stored up Locustidae, belong- 
ing to species of very different types ; all were young, 
and in some the wings had not begun to grow. There 
were nine in one chamber and six in the other, the two 
being separated by a partition partly of earth, partly 
of some soft brown substance of almost woolly texture 
whose origin was unknown. One Locustid of each col- 
lection had the Sphex's egg affixed to it on the under 
surface close behind the head. It is very interesting that 
this fossor, while abjuring the earth as a nesting place, 
still made use of it as material wherewith to form a 
partition between the two collections of prey. 

Another Sphegid with nesting habits unusual among 
this group is the extremely common and widespread 
Sceliphron spirifex, familiar in every house ; it is even 
found in South Europe. 

This rather elegant black and canary-yellow species, 
with long limbs and narrow pedicle to the abdomen, is 
classed as a " Mud wasp " by the annoyed housewife, 
from its habit of building a collection of earthen cells 
in any convenient nook, such as the fold of a curtain, 
the corners of open boxes, the back of a book, and such- 
like places. Like most Sphegidae, this energetic worker 
emits a curious note when working — a quavering, high- 
pitched buzz rising and falling slightly that is presumably 
made by quick vibrations of the wings as they lie upon 
the back. There are few houses in which this sound 
cannot be heard coming from some obscure corner. The 



296 HYI^IENOPTERA 

completed cell is about an inch and a half long, thick 
walled and smooth, with an internal calibre of an ordinary 
lead pencil. It is stuffed full of small paralysed spiders, 
on one of which the elongated egg has been deposited. 

The Sceliphron obtains its building material from a 
spot where the earth is damp, such as the edge of the 
lake, and gathers up in her mandibles a pellet about the 
size of a sweet-pea seed. With this she at once flies back 
to the chosen spot, and plasters it on to one end of the 
commenced cell, smoothing it with her mandibles very 
deftly, singing the while her high-pitched working song. 

No sooner has she used up the pellet than back she 
goes for another, until the cell is completed, save for the 
closing of one end, which is done when the stock of spiders 
has been brought. 

On Kerenge Isle, where spiders were exceedingly 
abundant, Sceliphron was also plentiful, and my grass 
hut was a very favourite nesting place, so that the high- 
pitched song of the worker was heard all day long. While 
sitting writing one morning I timed the journeys of one 
individual, noting the moment when she reappeared with 
a fresh pellet of moist building material, which she applied 
without waste of time, flying away again immediately to 
bring another pellet. 

The following are the times noted : 8- 45, 8- 48, 8- 50^, 
8-57i 91, 9-6, 9-8i, 912J, 917, 923^ 927, 930, 9-33J, 
9-36^ 9-39^ 9-41J, 944^, 9-47. After this she did 
not reappear for half an hour, and I went out. 

The average time taken to fly from the nest to the 
lake shore, collect a mud pellet, bring it back, and build 
it on to the nest was 36 minutes, the shortest being two 
minutes, the longest seven. 

Although the cells are often built singly, they may 
be aggregated, being built one alongside the other, so 
that a single mass the size of a small fist may be formed, 
comprising eight or ten cells, each stuffed with spiders. 



SCELIPHRON AND ITS PREY 



297 



It is quite extraordinary to think that all that material, 
weighing perhaps half a pound, has been brought by 
one insect. 

The destruction of spiders wrought by one Sceliphron 
in providing for a future generation is also surprising. 

On Kerenge Isle I counted the number taken from 
twenty -nine cells. In the following table a cell is indi- 
cated by a serial number, and all cells found attached 
together, i.e. built by one individual, are indicated by 
the same letter. 



lA 
2A 
3A 
4B 
6B 
6C 
7C 
SD 
9D 
lOD 



} 



.. 6 


IID 




8 


21G 


7 


12E 




. 12 


22G 


8 


13E 




8 


23H 


. . 25 


14F 




8 


24H 


16F 




8 


25K 


1 


16F 




5 


26K 


7 


17F 




4 


27K 


5 


18F 




6 


28K 


..12 


19 




. 12 


29K 


.. 14 


20 




. 5 





7 
9 
11 
14 
12 
15 
11 
11 
19 



The average number of spiders in a cell was 9-3, the 
minimum one, the maximum nineteen. The variation 
in the amount of food stored up is considerable, even in 
cells constructed by one Sceliphron. Thus No. 6 had only 
a single spider, very little larger than one of the seven 
in cell No. 7. The spiders are usually of a number of 
different species, but the twelve in cell No. 19 appeared 
to be the same. 

The destruction of spiders by Sceliphron must be con- 
siderable. Supposing that ten cells are completed during 
the lifetime of one individual, it will have accounted for 
about ninety spiders. 

Sceliphron itself, however, is victimized by a large 
" Ichneumon " fly of the same black and canary -yellow 
hues presenting a remarkable likeness to its victim, 
especially when seen on the wing at a little distance. 
Two- winged flies (Tachinidae) can also be reared from 



298 HYMENOPTERA 

Sceliphron cells, but they are probably indirect parasites, 
their larvae feeding upon the spiders and not upon the 
Sceliphron larvae, which thus die of hunger. 

A smaller species of Sceliphron makes cells somewhat 
similar to the mud nests built by S. spirifex, but they 
are placed upon grass stems and are of more delicate 
structure, being composed of some light friable material 
mixed with fibrous substance. These nests were common 
also on Kerenge Isle, and were filled with spiders. 

The great majority of Sphegidae, however, are true 
fossors — that is, they excavate burrows into which the 
paralysed prey is put. 

Since a Sphegid having once stocked the burrow pays 
no more attention to it, there is no need for it to work 
like Bembex in loose light soil ; indeed, the firmer it is 
the better they seem to like it, and often may be seen 
working on the hard surface of a trodden pathway. 

The methods of a Sphegid differ somewhat from those 
of a Bembex. The earth cannot be removed by mere 
scratching, but needs to be excavated by " tooth and 
nail." 

An Ammophila, for instance, having found a suitable 
site, commences to scrape together a little of the loose 
soil on top, which she holds between her front feet and 
head and, having walked backwards a few inches, deposits 
it with a little buzz of satisfaction and returns for another 
armful. Presently the soil is found firmer, and she sets 
to work with her powerful mandibles to loosen it, some- 
times bringing up portions in her jaws. The work pro- 
ceeds with rapidity until the hole descends vertically to 
such a depth that she disappears from view. 

She seems to be on springs, so full of life and energy 
is she ; it is often extremely curious to note how rapidly 
she shoots out from the burrow backwards, drops her 
load, and plunges headlong down the hole again as if 
drawn by a piece of elastic attached to the bottom thereof. 



AMMOPHILA 299 

Occasionally a piece of stone defies removal, and a pro- 
longed and angry buzzing from beneath the surface 
attests her efforts to dislodge it with her mandibles, but 
presently she works it loose and comes up with it. 

At last all is ready, and she proceeds to cover the mouth 
of the burrow before going off to seek the prey where- 
with to fill it. Pieces of stone of small size are selected 
and wedged together so as to block the entrance, and 
with her back to it she scratches a little loose earth over 
the stones and, after a final careful examination, flies 
away. 

Now you may see her quartering the ground for the 
caterpillar, grasshopper or other insect which she needs ; 
wings flicking and antennae quivering, she runs about 
eagerly searching until — pounce ! — she has found one 
and stung it, and it lies helpless on the ground, with 
limbs slightly twitching. 

Picking it up by her mandibles, unless it is too 
large, she walks with it back to her hole, keeping a 
marvellously straight course over all kinds of obstacles, 
even climbing with it up perpendicular rock faces, until 
after much effort she arrives at the site of the burrow. 
This is quite indistinguishable from the surrounding soil, 
but she knows it, for did she not herself take pains to 
conceal it before she left it ? The precious burden is 
put down, and the barricade that closes the burrow is 
removed. Down she goes head first, and presumably, 
after making sure that all is well, turns round in the 
chamber at the bottom, for almost immediately her 
head reappears and she seizes the prey and drags it down. 
After a very brief interval, during which the egg is laid, 
she reappears and at once sets to work to fill up the 
burrow. Standing with her head away from the open 
mouth, she vigorously scratches the loose earth back- 
wards into it with sure aim. But to make a good job 
of it something more is required, so she picks up pieces 



800 HYMENOPTERA 

of stone and puts them down the hole, and then proceeds 
to ram it all down in a most workmanlike manner. 

Firmly gripping the lips of the hole with her middle 
and hind legs, she launches herself with great force against 
the loose earth, using the front of her broad head as a 
battering ram, and making the loud buzz wherewith a 
great effort is signalized. At length the burrow is filled 
up flush with the surface, and it only remains to con- 
ceal the fact that the spot is in any way different from 
the surrounding terrain. Small stones are scattered over 
the surface, a little loose dust is scratched about, and 
the energetic Ammophila flies off to refresh herself on 
a neighbouring flower head before commencing to excavate 
a fresh burrow elsewhere. Unlike the Bembex, she will 
never visit her burrow again ; it has been adequately 
stocked with food once and for all. 

The above is a general description of the methods 
adopted by the majority of Sphegidae, and we will turn 
now to another great family of fossors, the Pompilidae, 
which is broadly characterized by rather longer limbs, 
and by the fact that they hunt spiders only. In essentials 
they work in the same manner as the Sphegidae, but so 
far as I can remember they work quietly, and never 
make the excited buzzing so characteristic of Sceliphron 
spirifex and other Sphegidae. 

But when it comes to the filling up of the stocked 
burrow there is an important difference in the manner 
of working, which I do not think has been sufficiently 
appreciated. 

As described above, a Sphegid uses the front of her 
broad head as a battering ram wherewith to press down 
the loose earth ; but Pompilidae invariably use the end 
of the abdomen. 

Sometimes the insect stands in the mouth of the hole 
and quietly presses down the soil in the burrow, but one 
specimen that I saw threw her body into such quickly 



POMPILIDAE 301 

repeated movements that her outline became blurred, 
and she reminded one of the rapid oscillations of a 
pneumatic hammer.^ 

Perhaps Pompilidae do not use the front of the head 
because it is less broad and flat than in Sphegidae, and 
therefore does not form such an efficient rammer ; but 
the difference is extremely remarkable. 

The Pompilidae are most typically aposematic insects. 
Many are of intense blue-black with shining bluish or 
greenish black wings, often set off by canary-yellow 
antennae. The sting inflicts a very painful wound, but 
they do not use it unless molested, and may be watched with 
perfect immunity so long as they are not roughly handled. 

It is difficult to conceive a more conspicuous insect 
than one of these fine creatures as it sails through the 
air with its long legs hanging down. Yet according to 
some of the American naturalists these insects are con- 
cealed by resemblance to their surroundings. 

In that case it is difficult to explain one of the most 
striking characteristics of these large Pompilidae, namely, 
the extraordinarily noisy flight, which is often a loud 
rattling or clicking noise audible before the insect is seen, 
and reminding one of a badly made piece of clockwork. 

If a Pompilid is really concealed, what is the meaning 
of this noise which at once directs attention to it ? 

If, on the other hand, these insects are really highly 
conspicuous, as I think, the loud noise is merely an 
adjunct to their aposematic colouration, and serves still 
further to advertise their owner's unpleasantness. 

Many times have I seen my pet monkeys' attention 
caught by the noise of one of these formidable insects 
on the wing, and they would turn their heads to the 
direction from which it came, and watch the Pompilid 
when it came into sight with the most careful attention, 
being evidently anxious to avoid it when it drew near. 

^ Batozonus fuUginosus. See Proc. Ent. Soc. Lond., 1917, p. Ix, 



302 HYMENOPTERA 

This *' aposematic noise " is entirely in keeping with, 
and explicable by the same means as, the conspicuous 
appearance of the insect, which is thus enabled to appeal 
to more senses than one. But if the Pompilid is con- 
cealed, then one explanation is required for its colour 
and another for its noisy flight, though it is difficult to 
imagine what explanation of the latter could be given. 
I have suggested elsewhere ^ that there is an analogous 
example among birds in the case of the large black and 
white " E'nga-nga " hornbill, whose wings make an extra- 
ordinary roaring noise as it beats them, or sails with 
them outspread through the air, often at the same time 
calling attention to itself by its loud raucous cry. 

It has been mentioned in the case of the Bembecidae 
that they have enemies in certain flies, and the same 
holds good with Sphegidae and Pompilidae. 

The golden moment for the enemies of these fossors is 
when they have arrived with their burden at the mouth 
of the burrow and leave it outside while they go down. 
The attendant fly can then dart down and deposit its 
own egg up'on the prey while the fossor is busy, and that 
it does so is evidenced by the fact that on grasshoppers 
taken out of the burrows of the little Sphex marginatus 
I found dipterous larvae which became flies of a species 
unknown to the British Museum, but alUed to the Milto- 
gramma described by Fabre. It is rather interesting 
that whereas most fossors seem to take little notice of 
other insects while they are at work, Sphex marginatus 
is extremely suspicious of any intruders on its privacy, 
and charges fiercely with open mandibles at even the 
smallest ant that draws near to its burrow, much to the 
dismay of the quite inoffensive ant ! If the trespasser 
does not at once withdraw, the Sphex makes threatening 
movements as if about to sting, turning the tip of her 
abdomen forwards between her legs. 

» p. 168. 



MUTILLIDAE BEES 303 

Another family of fossors, the Scoliidae, has been men- 
tioned because they save themselves a great deal of 
labour by searching out the food for their larvae and 
laying an egg on it in situ. 

They are interesting also from another point of view, 
because, of all Hymenoptera, they have the quietest flight ; 
even the largest specimens produce a barely audible hum, 
thus contrasting greatly with Pompilidae. They are 
usually rather solidly built, hairy insects, sometimes 
black, sometimes reddish or yellowish in colour. 

Lastly, there are the Mutillidae, which will only be 
mentioned on account of their scarcity on the islands. 
It seems that forested country and a damp climate are 
not so suitable to them as the more open bush country 
with regular dry seasons such as occurs in much of ex- 
German East Africa, where I found Mutillidae far more 
abundant than on the islands. They are remarkable 
among Hymenoptera for the complete absence of wings 
in the females, which are often mistaken for ants as they 
run quickly over the ground. A species of Methoca was 
obtained which was not in the British Museum collection : 
the few African species that are known of this genus 
had previously only been obtained from south of the 
river Limpopo. 

Regarding Bees I have little to say. The very hand- 
some large " Carpenter bees " {Xylocopidae) , . which in 
the tropics take the place of our " Bumble bees " 
at home, are plentiful enough, and may often be seen 
visiting the large yellow flowers of ambatch trees. A 
particularly handsome large one is covered with bright 
golden brown hair ; this is the male of a species whose 
female is black and white. Their burrows in dead 
trees are commonly seen. The natives call them 
" Buvumira," which is quite descriptive of a large 
buzzing insect. 

A smaller bee {Crocisa meripes) presents a great con- 



304 HYMENOPTERA 

trast to these furry fellows, as its integument is hairless, 
and brightly coloured sky blue and black, 

I do not know where Crocisa nests, but it has a remark- 
able habit of passing the night in the open on a grass 
stem, its mandibles firmly clasped round the stem, and 
its legs tucked up against the body, so that the insect, 
supported only by the grasp of its mandibles, projects 
obliquely from the stem. They may often be found dead 
in this position. 

Sometimes several will affix themselves thus, one 
below the other, and the stem may be picked and carried 
about without disturbing the bees. Another species 
{Coeliaxis carinata) has the same resting habit. The 
islands are singularly blest in the absence of minute, 
stingless, but very annoying bees (Melipona), commonly 
known as " Sweat bees," from their habit of settling on 
one's bare skin and licking up the perspiration. If they 
would only settle quickly one would not object so strongly, 
but they spend a long time dancing about in front of 
one's face under the brim of one's hat ; when they do 
settle they cause an intolerable tickling. 

Though they have lost their sting they are very possibly 
still protected, for if one is squashed by a blow it has 
an unpleasant acrid odour. I first made their acquaint- 
ance on active service, and soon learnt to give thanks 
that the islands did not support them ! 

Like the Mutillidae they seem to prefer more open, 
drier country ; hence the thirst which leads them so 
eagerly to suck up moisture from one's skin. 




P'LY BOYS CAMP ON KOME ISLE, I9I4. 




SERVANTS' HUTS ON KOME ISLE, I9I4. 



To face p. 304, 



CHAPTER XIII 
SUNDRY INSECTS 

COLEOPTERA. 

Beetles were not systematically collected on the islands, 
so that there is not so much to be said about them as 
about Lepidoptera. 

The first interesting specimen that was met with on 
the lake shore was a new species of Coprid, which Mr. 
Arrow informed me was quite unlike anything in the 
British Museum. I was watching a column of the 
" Safari " ant (Dorylus) moving from one camp to 
another, carrying their pupae with them, and saw this 
flat, black, highly polished beetle running in the column 
among the ants, who took not the slightest notice of it. 
That it did not belong to them was improbable, for it 
took the greatest care to remain in the column, and 
these ferocious ants most strongly resent the presence 
of any stranger among them. It is interesting to find 
that these dread hunters have their familiars. Possibly 
the larva acts as a useful scavenger in their nests, as does 
the larva of the Rose beetle in nests of other ants. 

While at Jinja in 1910, I watched with interest the 
behaviour of some large polished green Coprids engaged 
in making their balls from the recent droppings of some 
grazing animal. 

When I first came up one had almost finished 
making its ball. When it was finished the beetle pressed 

21 30» 




806 SUNDRY INSECTS 

the material together with its front legs and then very 
cleverly rotated it on one spot, lying almost underneath 
it, so as to get a firm coating of earth on it ; it then 
trundled the ball away. Soon other beetles arrived on 
the wing, dropping quite near to their objective and 
eventually crawling to it, obviously guided by smell. 
If one happened to meet another when both were search- 
ing for the dropping, one always fell in and followed 
behind as if quite certain that the other must know the 
way ! I watched No. 2 make its ball. The desired 
portion of the dropping was the outer part which had 
hardened somewhat. The beetle stays at one spot and 
reaches towards it with its powerful forelegs enough 
to make a ball about the size of a very large cherry. 
It frees it below by insinuating the sharp front margin 
of the head between the ball and the mass, and making 
powerful lifting movements of its head. 

No. 2, after making the ball, did not for a long time 
push it away, but kept pressing it together and patting 
it, and finally gave it a very smooth coating of fine 
earth, and then sat resting on it. 

Meanwhile others had arrived (ten altogether came 
while I watched), some smaller in size. One of them. 
No. 3, apparently desired a share in No. 2's ball, but 
was driven off, hurled away by jerks of the strong front 
legs. Eventually it joined with another small one, 
No. 4, and these two very quickly made a rather ill- 
constructed ball and trundled it off, No. 2 still patting 
at its own. 

There were numerous fights between the workers, who 
sometimes got mixed and each took the other's ball. 

These beetles are eaten by a species of Roller, one 
of which when shot was found to have several of them 
inTits stomach. Presumably its powerful bill enables it 
to. feed on such horny beetles, whose large size and hard 
coat of mail must deter smaller birds. Of the carnivorous 



BEETLES 307 

ground beetles I saw little on the islands, but two species 
of Cicindelidue (Tiger beetles) were found, which were 
very acceptable to the British Museum. One, a pretty- 
green species, not unlike the English G. campestris, but 
larger, was found abundantly running over termite hills 
on Nsadzi Island. The other was a mottled grey species, 
found, but very difficult to see, on a stretch of sand on 
Bugalla that had at one time obviously been the lake 
shore. The huge black Cardbidae,^ common in Africa, 
were never seen on the islands ; though I do not assert 
that they were not there, it seems curious that they 
should never have been met with. 

Carnivorous water beetles {Dytiscidae, Gyrinidae, etc.) 
were of course abundant in the weedy shallow waters. 
The readiness with which they take to the wing is well 
known ; but it was quite amusing to note how, during 
a storm of rain, several Gyrinidae appeared in the trench 
which led away the rainfall from the roof and solemnly 
executed their well known whirligig manoeuvres so long 
as the water lasted, and when the storm was over they 
vanished. Large Dytiscidae several times dropped on 
to a shiny patch of wet ground during heavy rains, 
evidently misled into thinking it was a pool. 

The beautiful Longicorn beetles were often met with, 
and one very abundant green species of medium size ^ 
had a very rank aromatic odour, and my pet monkey 
would not eat it. 

The most interesting Longicorns are the mimetic 
species, and a very fine one ^ was abundant on the 
flowering shrub Haronga, where it was associated with 
the large Lycidae which it so much resembled. Other 
Longicorns mimic the parasitic Hymenoptera of the family 
Braconidae, many of which are typically aposematic in 
appearance, and have a powerful, rank odour. 

^ Genus Anthia. ^ Phrosyne brevicornis. 

' Amphidesmus analis. 



308 SUNDRY INSECTS 

A common colour scheme for large Braconids is orange 
and black, and on Bugalla a Longicorn ^ beautifully 
mimetic of these was found. Being long and narrow, 
the beetle has a shape which affords a good basis for 
the resemblance. The orange abdomen, however, does 
not show the narrow waist of the Hymenopterous model, 
to which the resemblance is produced by a portion of 
the side of the base of the abdomen being of a glistening 
white, contrasting strongly with the remainder, so that 
that part in a high light suggests that it has been, to 
use Professor Poulton's phrase, " painted out." The 
first specimen that I found was a male which when 
handled strongly curved the tip of the abdomen in such 
a way as to suggest it was about to sting, and actually 
protruded a flexible white viscus which it moved about 
like a sting. Of course Braconidae are not strictly 
stinging insects, yet when handled they will use the 
ovipositor as such. The Hymenopteroid appearance of 
the beetle with its false sting was so very striking that 
although reason told me it was a beetle, instinct was 
so strong that misgivings almost prevented me handling 
it, and I feel certain the very great majority of people 
would have dropped the beetle in a panic. On the 
wing the resemblance is much greater ; both insects 
have a slow, steady flight, and the long antennae are 
extremely conspicuous. The wings of the beetle are 
transparent and invisible during flight, but the orange, 
black-tipped, wing covers reproduce the appearance of 
the similarly coloured wings of the Braconid. Several 
smaller species of Longicorns also very closely resemble 
smaller black and yellow Braconids, so that even after 
several years of field work one is still deceived and, 
catching an insect which one has thought to be a Braconid, 
finds a beetle in the net.* 

* Dirphya, species near pHnceps. 

' This happened to me repeatedly in 1917 in Gennftn East Africa. 
See Proo. Ent. Soc, 1918, pp. cxxxviii-cxlii. 



BEETLES 309 

Many Braconids are coral pink and black, and they 
also are mimicked by small Longicorns. On Bugalla 
I obtained model ^ and mimic ^ at the same spot and 
time, and also a small Capsid bug,' equally mimetic. 

Fireflies are interesting beetles, but, having read much 
about the wonder of tropical fireflies, I was much dis- 
appointed on the islands ; only a few were seen at a 
time, belonging to a species looking much like the male 
of the English glow-worm, and I have seen a much better 
display in the spring on the Riviera. 

Wood-boring beetles are a great nuisance in a house 
constructed of freshly cut boughs and stems of trees ; 
the rafters are soon penetrated in every direction by 
tunnels, from the open mouths of which a continuous 
stream of the finest sawdust falls and soon covers any- 
thing left lying for long in one place. 

Quite the most remarkable beetle met with on the 
islands belongs to the aberrant family Lymexylonidae,^ 
it several times appeared in my hut in the evening, 
flying with sonorous buzz, and the first time I saw it 
puzzled me not a little, for it was like no beetle I had 
ever seen or heard of at that time. 

The very long, thin body was quite soft and flexible, 
and a very short pair of wing covers entirely failed to 
cover a long pair of wings with stout longitudinal 
rays so that they folded like the wings of a grass- 
hopper, but then projected far behind the covers. The 
legs were long and thin, and the antennae short, with 
broad flat segments. 

Neuroptera. 

Dragon flies are, of course, abundant on the lake shore, 
but I do not think they are any more noteworthy than 

^ Not yet identified. 

• Dirphya, species near pascoei, Lamiidae. 

• KolopeUis bergrothi. * Atractocervs brevicornis. 



310 SUNDRY INSECTS 

our beautiful English species. One fine, abundant species 
is blood red, and another is vividly coloured with cobalt 
blue and red, but there are many dull species. One of 
these,^ the commonest of all, may be seen on the wing 
before sunrise and after sunset, and on one occasion on 
Kerenge Island I saw a host of them about sunrise, 
dancing up and down in the air just as Mayflies do 
in England. 

The large species of Dragon flies often prey on the 
smaller, as well as on bees and other protected insects. 
I have seen Cacergates preying on Glossina, and since 
both large and small Dragon flies are favourite articles 
of food of the bee-eater Merops super ciliosus, the 
bionomic relation of this bird to the Tse-tse fly is rather 
a complicated one ! 

A curious Neuropterous insect named Bittacus was 
attracted to light several times on the islands ; it is a 
slender light brown species with narrow wings and very 
long slender legs. On the first occasion I thought it 
was a Tipulid, and did not take much notice until some- 
thing about it made me look more closely, and I saw it 
was not a " Daddy longlegs," but had four wings. 

If there was any reason for supposing the TipuUdae 
to be protected one might consider the Bittacus to mimic 
the fly ; but there seems no reason for supposing that 
a resemblance to a " Daddy longlegs " would be of any 
benefit. 

A remarkable genus of Neuroptera is named Mantispa. 
These insects resemble Mantidae, and have the fore limbs 
modified in the same manner for holding the prey, which 
they devour alive. Several of them very deceptively 
resemble Hymenopterous insects. On Kome, one day, 
I saw on a twig an insect that at first appeared to be 
one of the abundant, conspicuous and fiercely stinging 
wasps of the genus Belonogaster. It was munching at 

^ Cacergates leucosticta. 



MANTISPA 311 

some insect it had caught precisely as the wasp chews 
up caterpillars into pulp, and when disturbed flew with 
it on to a neighbouring branch. But the thickness of 
the abdomen caught my attention, and disclosed the 
true nature of the insect. The question may well be 
asked. How was it that the broad wings of a Neuropterous 
insect did not attract attention, as differing from the 
narrow folded dark wings of the wasp ? 

When the Mantispa was at rest the fore wings 
lay above the posterior wings and concealed them. 
Their greater part was absolutely transparent and 
hardly noticeable, but the appearance of the narrow 
wings of the wasps was produced by a darkening of a 
narrow strip along the anterior margin of the fdre wings, 
which dark strip roughly resembled in shape the whole 
of the folded wings of the wasp.^ The Mantispa at rest 
held its wings directed backwards as does the wasp, 
but not quite parallel to the body, so that they made a 
slightly greater angle with each other than did the 
wasp's wings. 

In colour the Mantispa very closely resembled Belono- 
gaster, and the resemblance, probably pseudaposematic 
or true mimicry, was extraordinary, and would not be 
believed if one had only seen the specimens in the cabinet. ^ 

Orthoptera. 

Mantidae. — One species, Pseudocreobotra ocellata, has 
already been alluded to as an instance of Anticryptio 
colouring ; other equally cryptic grass green species 
were particularly abundant on certain islands, an account 
of which was given in Chapter VI. Sometimes the 
curious egg clusters were very abundant ; the eggs are 
embedded in a substance somewhat resembling the crust 

1 See also Trans. Ent. Soc. Lond., 1902, Part III, pp. 528-9. 

8 Cp. G. A. K. Marshall, Tratis. Ent. Soc, 1902, Part III, pp. 636-7. 



312 SUNDRY INSECTS 

of a meringue, covered by a substance resembling parch- 
ment in texture, but produced by the Mantis as foam 
at the time of oviposition. These egg masses vary much 
in shape, size and texture according to the species — some 
are pure white, spherical, and about the size of a bantam's 
egg ; others, no larger than a hazel nut, have an amber 
coloured, almost transparent covering, with a ridge along 
one side looking like a seam where two halves meet. 
These are very conspicuou^s, and may be seen at the tips 
of twigs, etc. ; but there are other very cryptic forms 
of egg masses, laid along a twig and closely adherent to 
it, with rough opaque brown surface. The freshly hatched 
Mantids may sometimes be found hanging from the 
egg clusters by slender threads, but I do not know 
for how long they remain thus. Very young specimens 
are often black, and look extremely ant-like as they run 
about. 

Phasmidae. — Stick insects found on the islands are 
small and not remarkable : " grass insects " would be 
a better name, because they are found in long grass, the 
stems of which their slender wingless bodies resemble 
in size and colour. They frequently betray themselves 
by a curious swaying from side to side, for which it is 
difficult to account, for were they to remain quite still 
they would certainly be invisible. 

Locustidae. — The most noticeable insect of this family 
was a slender active grasshopper known to the natives 
as " Ensenene " ; about two inches long, usually grass 
green but sometimes light brown. These grasshoppers 
used to appear suddenly in great numbers and could 
be heard faintly chirping in the grass. As one walked 
along they took to the wing in clouds, and their 
pearly wings flashing in the sun produced a curious 
resemblance to driven snowflakes. At these times the 
natives would go out and catch large numbers for eating, 
walking through the long grass and whistling through 



ORTHOPTERA 313 

their teeth to make a sibilant noise. They were prepared 
for food by frying. My pet monkeys were also exces- 
sively fond of them, and would eat them for as long as 
they were offered, even until the overloaded stomach 
rejected them. 

A ghoulish species of Ephippigeridde was a great 
nuisance in my hut on Damba, as it found its way into 
every box of food and quite replaced the kitchen cock- 
roach as a pest. It has a rotund short body with im- 
mensely long limbs and antennae, and is offensively 
familiar ! It would come on to the table while I was 
dining in the evening and stand with the filamentous 
antennae waving in the air, and was so quick that I 
could never catch it before it leapt away. As it 
was a great nuisance I was glad to find that the egg 
cases, like little portmanteaux, were attacked by a 
Chalcid parasite, which laid its own eggs inside the case. 
One such, when opened, was found packed with rows 
and rows of the minute white pupae of the parasite, white, 
with shining black eyes, looking for all the world like 
neatly arranged mummies. The male of this species has 
imperfect wings, and has not been heard to make a 
noise. 

Another very large burrowing species during the rains 
sits at the mouth of its burrow making a continuous 
'* shrilling " noise which, if at all close, is quite un- 
bearable, as it seems to make one's whole head vibrate 
in sympathy. 

Another Locustid worthy of notice, of the same section, 
is known to the natives as " Semukutu." It is disliked 
very much by them, for they say it bites and makes sore 
places, and often show sores which they say were caused 
by a Semukutu. When handled this insect ejects with 
some force from the side of the thorax a stream of 
clear, yellow fluid with an acrid smell, but though I have 
handled a large number in the endeavour to collect a 



314 SUNDRY INSECTS 

quantity of the fluid I have never suffered in any way 
from it. No doubt it would be excessively unpleasant 
in the mouth or eyes of an enemy. The Semukutu is 
a large, fat, bloated creature destitute of any trace of 
wings, and with spiny thorax. Young specimens are 
often greenish, but the adult is dull brownish grey. It 
is a very sluggish insect, and freely exposes itself as it 
crawls heavily about. 

Acrididae. — Large and powerful grasshoppers of this 
family, species of Cyrtacanthacris, are known as " Ama- 
jansi " to the Baganda. Some of them are several inches 
long, and were apparently much esteemed as food by 
the monkeys. They were not noticeably abundant on 
aU the small islands visited, but seemed to be so on 
Kerenge, where the beautiful bright blue kingfisher that 
feeds on them was much in evidence. 

Blattidae. — Cockroaches of many species were common 
among dead leaves in the forest, but one saw little of 
them except when the " Safari ant " was out hunting. 
Then the unfortunate cockroaches, driven from their 
lairs, rushed hither and thither in frantic desperation, 
and in such a state of panic that they often tumbled 
head over heels, and the more easily fell a prey to the 
host of ants, which at once tore them to pieces. Some 
curious species may be found half buried in loose dry 
earth at the base of trees ; absolutely wingless, they 
look much like huge woodlice. 

Dermaptera. 

The earwig family was not at all well represented on 
the islands, much to my surprise, for there seemed to 
be ideal conditions for them. I thought at the time 
that perhaps this was the rule in equatorial Africa, but 
later modified this view when on active service in German 
East Africa, where earwigs were found extraordinarily 



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cook's uut (left) and kitchen on bugalla. 
Cook on right. The water boy on the left developed sleeping sickness. 




HEAD KoV (A SWAIIII II A Nl > ^I-.i;(jN1i liuV (mL'GANDA) ON RIGHT. 
Their wires had come out for a brief visit. 



To face p. 314. 



FLIES 315 

abundant in some parts of the country. So that the 
islands would appear to be unfavourable to them. 

One large species was found on Damba under a stone 
at the very water's edge, so that the tiniest ripple must 
have surrounded it. 

DiPTERA. 

The most important fly on the islands, namely Glossina 
palpalis, has had a chapter to itself. Other biting flies 
{Tabanidae) were less common on the islands than on 
the mainland, but T. variabilis a small black and white 
species, and Chrysops brucei were occasionally seen, with 
one or two species of Hcematopota. 

Mosquitoes, of course, were to be reckoned with, and 
they were particularly abundant on Damba Island, 
perhaps because it was covered with low lying forest. 
But the Anophelines, carriers of malaria, were so 
scarce that the numbers of times one was seen could 
be counted on the fingers, so that the health of the party 
was excellent. The Simuliidae, or " Buffalo gnats," have 
been alluded to as particularly troublesome on certain 
islands when rain was threatening ; they frequent rocky 
open shores, and when abundant render such spots un- 
approachable. The species found on the islands was 
not the same as the one I had previously met at Jinja, 
S. damnosum, called " Embwa " by the natives ; the 
island Simulium is smaller and rather prettily coloured 
with golden pubescence. Both leave a severe burning 
and itching sensation, but whereas S. damnosum attacks 
particularly the lower extremities, the island species 
makes for one's head and neck, and especially the ears. 

The parasitic Tachinidae, which lay their eggs on the 
surface of living insects, have been briefly alluded to as 
enemies of " protected " insects. 

On one occasion a species was observed in the act of 
oviposition. 



316 SUNDRY INSECTS 

On the minute island Lula, several colonies of very 
hairy caterpillars, of the family Eupterotidae, were seen 
on trunks of trees. Near one colony was a large Tachinid 
fly, and the caterpillars, close together, seemed to be 
aware of her presence, for they moved uneasily ; but 
the fly moved as they moved, sidling about in a very 
amusing manner so as always to face the caterpillars. 
She endeavoured to find one that was not moving, 
and then approached the head from in front. The long 
hairs of the caterpillar projected from all parts except 
the head, so as to form a chevaux de frise, but opposite 
the head there was a small gap in the barrier. The fly, 
having approached as close as she could, raised herself 
up on her anterior legs and protruded forwards, beneath 
herself, an enormous ovipositor whose tip projected in 
front of her head. The egg was laid in a very brief instant 
on or near the head of the caterpillar, but sometimes 
the fly was unable to reach its head, and then had to 
wait until the larva was near enough for her ovipositor 
to reach between the long hairs so as to deposit an egg 
on the flank of the larva. 

It was a most interesting and instructive proceeding, 
illustrative of the adaptation of one enemy (the fly) to 
meet a condition in its victim probably directed against 
other enemies (birds). It was noted that the fly laid 
its eggs fortuitously on any larva that presented itself, 
so that one received many eggs but others none. This 
might quite well lead to some of the offspring of the fly 
receiving insufficient nourishment and being stunted in 
growth or failing to develop. One sometimes meets the 
opposite condition, when too few ova have been deposited, 
and the parasites have not damaged the vital parts 
of their host. I once reared a single Tachinid fly from 
an Arctiid larva which eventually produced a perfect 
moth ! 

Asilidae or Robber flies were often met with at the very 



FLIES 817 

margin of the forest where it abuts on open grass land ; 
others in the forest, and others on the grass land. Robber 
flies seems a poor name for these powerful, hairy, pre- 
daceous flies, with long narrow bodies and strong legs. 
Hawk flies would be a better name, seeing how they 
pounce upon their prey ; in some six years of work in 
the field I can only once remember seeing an Asilid 
pounce on its prey sitting. 

Emphasis has already been laid upon the importance 
to the theory of mimicry of noting the prey of Asilidae. 
It is, I think, quite certain that the fly injects poison 
into the victim the moment it has been captured and 
the proboscis has been plunged into it. The prey seems 
to succumb at once before it can have been sucked dry, 
and if one actually witnesses the capture and at once 
catches both insects the prey is almost always found 
to be dead, or feebly moving its legs only. Only once 
have I met with an exception to this. An Asilid was 
seen to catch a bug, and I struck at it with the net. The 
fly escaped, but dropped the bug, which was found to be 
apparently unharmed. 

Another family of Diptera, Chironomidae or " gnats," is 
worth mentioning here, owing to the abundance in which 
they appear over the lake during and shortly before the 
rainy season, resembling clouds of smoke from distant 
steamers. I have seen, on a calm day, a large area of 
water covered by the pupal skins of these flies, the pupae 
having come up irom quite deep water, and the flies 
rising in a cloud from the surface, which was of a brown 
tint from the myriads of empty skins. When these flies, 
called "E'sami" by the natives, and looking more or less 
like mosquitoes without the sucking proboscis, have 
drifted in a cloud on to some land they find shelter from 
the wind on the lee side of trees and bushes, where they 
may be seen hovering in a cluster, the end of which, 
furthest from the tree, is strung out and torn by the wind. 



318 SUNDRY INSECTS 

On a very calm and damp clouded day the air is filled 
with the high piping of the Sami, hovering in myriads 
in the shelter of bushes, and a sudden noise will cause 
them all to rise suddenly upwards. It was very amusing 
to sing a scale, for one note appeared especially to upset 
the Sami, and when it was reached every member of 
the hovering cloud would simultaneously leap an inch or 
so upwards. The natives catch large numbers in baskets 
like strawberry baskets made of plaited grass through 
which a stick is passed ; the whole is vigorously waved 
about in a cloud of Sami, the basket rotating around the 
stick, which passes across its diameter. The catch is 
compressed into a cake, but I do not know how it is 
prepared for food. 

Sami have an odour of the lake which it is difficult 
to describe — a smell like weeds and fish from a muddy 
pool ; it is a common saying at Entebbe that the arrival 
of clouds of these gnats produces an outbreak of nasal 
catarrh among the white inhabitants ; possibly this is 
of the nature of " hay fever." 

Spiders. 

The most noticeable fact about spiders on the islands 
has been already recorded in the account of the tour 
in 1914, namely, the extraordinary abundance on certain 
islands of the huge Nephila, and the sheets of their webs. 
It was noteworthy that on some of the islands the spider 
was present in normal numbers only, as on Kibibi. Spiders, 
generally, are called " Nabubi " by the Baganda. A 
curious habit has been noticed in the case of a species, 
making the typical " orb web." Over part of the web 
it would spin a piece of very conspicuous, opaque, glisten- 
ing white silk, which was visible from some distance 
away. The design in the same web would be changed 
from time to time, for sometimes there would be an 



SPIDERS 319 

opaque bar right across the diameter of the web, or at 
others a zig-zag between two of the radii only. The 
reason for this is obscure ; I can only suggest that it 
is analogous to the trapper's artifice of putting an object 
across the track of some animal which, making a detour 
to avoid what it imagines to be a trap, falls into the real 
trap set at' the side. An insect on the wing, supposedly, 
sees the conspicuous part of the web, takes care to fly 
past the side of it, and is caught in the inconspicuous 
part which it has not seen. 

On an earlier page attention was directed to silver 
markings on insects ; a spider found on Dwaji Isle in 
1919 was notable. It was of fair size and spun its web 
among heads of dry grass ; the colour of the cephalo -thorax 
and front part of the abdomen was pure silver, the rest 
of the abdomen was dark, but speckled with yellow and 
with a series of silver bands ; the legs were banded alter- 
nately dark and speckled-yellow. 

Of the smaller members of Arachnida, Ticks call for 
notice, but only on account of their great scarcity on 
the islands. This is presumably associated with the 
absence of cattle and all buck except the Situtunga ; 
and if the islands could be again inhabited it should be 
possible to keep cattle there free from ticks and therefore 
from the diseases carried by them. 

The Varanus often has numbers of ticks on it, but 
these are not of the species which feed on cattle ; 
prettily decorated ticks ^ have also been found on the 
Horned Puff Adder. The islands are also singularly 
blest in the absence of Scorpions, which were not met 
with ; possibly the climate is too continuously humid 
for them. 

The great group of Myriapoda calls for passing 
notice, firstly because of the absence of the huge 
centipedes found in some parts of Africa, and secondly 

^ Aponomma Iceve. 



820 SUNDRY INSECTS 

on account of the great abundance of giant Millipedes 
(" E'gongolo "). These fine creatures, with cylindrical 
bodies some six to eight inches long, as thick as one's 
finger, clothed in rings of polished black armour with 
reddish legs, are really extremely handsome. They may 
often be seen on the sandy beach feeding on decaying 
rubbish cast up by the waves, and are especially notice- 
able when rain is coming. They were not met with on 
certain of the smaller islets, which were yet of suflBcient 
size to be expected to support them. 

I think that they are occasionally devoured by the 
Enswa-swa, for rings of their armour may be seen in dried 
excrement believed to be of that reptile. But I am 
quite unaware what are the main checks on the increase 
of these millipedes ; possibly the greatest loss is caused 
by enemies that devour the eggs, or parasites of the eggs. 
It is a curious fact that I cannot remember having seen 
a specimen less than half grown. 

Crustacea. 

Small crabs are one of the factors of the lacustrine 
fauna which suggest the sea, and they are abundant in 
shallow water. Superficially they much resemble crabs 
of a couple of inches in diameter that one finds in 
seaside pools. The natives call them " Enjaba.^' One 
was found under a stone among damp debris about 
twenty yards away from the water, a young and lively 
specimen. 

Crayfish were never met with, but shrimps, looking 
much like the common marine species, abounded in 
shallow weed grown waters. 

The natives call them " Obuduli," and use them as 
bait for fish, but I do not think they eat them. 

Fish lice, of two species, were met with on the " Mamba " 
and " Mal§ " fish already described, and specimens sent 



i 



MOLLUSCS 321 

to the British Museum proved to be of some value and 
interest.! 

Woodlice, like other creatures such as earwigs, scor- 
pions and centipedes, usually regarded as objectionable, 
were exceptionally scarce on the islands, and this was 
very surprising, for one would have expected a com- 
paratively equable, damp climate to afford favourable 
conditions. 

Molluscs. 

The lake shore abounded with univalves and bivalves 
which had quite a marine appearance ; securely fastened 
to rocks was a species resembling the common oyster. 
Besides these were others very closely resembling our 
English genera of fresh-water snails and mussels. 

A curious slug, that had very short tentacles 
and seemed to have no " mantle " at all, was found 
slowly crawling on wet sand, where also the large Ampul- 
laria were occasionally thrown up by waves. Shells of 
these large molluscs may be found on the lake shore, 
apparently battered to pieces on a stone as our garden 
snails are by thrushes. I strongly suspect this to be 
the work of the " open-bill " stork. 

On Damba Island there was found quite commonly a 
snail of the type of our English Vitrina, but very much 
larger, with a thin fragile shell practically enveloped by 
extensions from the mantle. This was easily procured in 
numbers when the " Ensanafu " ant had been hunting, for 
its only means of escape was to crawl upwards. Should 
it happen to come to the top of a stem it was unable to 
descend again and face the ants, so defended itself by emit- 
ting bubbles to form a mass of foani completely surround- 
ing itself, which the ants could not penetrate, and if they 
bit into it they could reach nothing solid. These white 
masses of foam, like " Cuckoo spit," were very con- 

^ Dolops ranarum and Argulus ajricanus. 
22 



322 SUNDRY INSECTS 

spicuous in the forest after a raid by the Ensanafu. Speci- 
mens sent to England were found by Lieutenant-Colonel 
Godwin- Austen, F.R.S., to be a species hitherto un- 
described. On Tavu Island, among dead leaves, I once 
found a minute snail like a Vertigo, but lost it again. 

A very large snail {Achatina) with pointed shell of 
brown colour, the mouth tinted with purple, was common 
on Damba, and I once disturbed an Enswa-swa which 
had apparently been much interested in one that was 
laying its eggs in the ground. It is possible that the 
eggs were the attraction and not the snail ; they were 
a little larger than a pea, but not spherical, with a firm 
shell of canary-yellow colour. 

The general name for a snail in Luganda seems to 
be " E'sonko:' 



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INDEX 



Abdimia abdimii, 155 

Achatina, 97, 822 

Acraea, prey of Belongaster, 285 

alciope, variations in, 235, 240, 241 

egina, 103, 120, 205 
as model, 233, 238 

encedon, 109, 110, 112, 120 

jodutta, as mimic, 233 

nataliea, courtsliip of, 224 
pseudegina, 120 

pentapolis, 104 

perentia, 205 
as mimic, 233 
larvae of, prey of bug, 219 

terpsichore and Syntomid moth, 222 

zetes, 116, 120, 205 
parasites of, 220 
as model, 233 
Acraeinae (see also Acraea, Planema), 
103-5, 109, 110, 112-5, 120, 125, 
205 

emit distasteful fluid, 210 

toughness of, 225, 213 

courtship of, 224 

nuptial flight of, 225 

as models and mimics, 233, 242 
Acrididae, 136, 314 

aposematic, 209-12, 215 
ActophUus africanus, 153 
/Sna, 159 
Agamidae, 185 

(" Akalerwe ") (see Hydrochelidon), 146 
(" Akamunyi ") (see Milvus), 161 
(" Akasalu ") (see Galactochrysea), 150 
" Akasonzi," 141, 194 
(" Akatassa ") (see Lily Trotter), 153 
(" Akawundo ") (see Bat), 143 
Albert, Lake, 68 
(Akkornea) (see " Oluzibaziba "), 70 
Aletis erici, larvae of, 214 

evidence of insularity, 103, 106 
Aloe, evidence of insularity, 116 
(" Amajansi ") (see Cyrtacaiitfiacris), 314 
Amauris, as models, 242, 268, 273 

Mendelian relationship in, 268-9 
Amauris echeria, 114 

evidence of relative inedibility of, 238 

niavius, 103, 114, 222 

psyttalea, 114 
courtship of, 222 
Ambatch, 70, 9ft-8, 108, 111, 117, 121, 122, 
147, 158, 176, 194, 303 

flowers, 165, 303 
Ammophila, 298-300 
Amoeba, 11 

Amphidesmus analis, 307 
Ampullaria, 154, 184, 321 
Anal tufts of Amauris, in courtship, 222 
Anastomus lamelligerus, 97, 109, 146, 164 

323 



Andronymus leander, 110 
Anhinga rufa, 148 

Ant (see alsoDorylus, Megaponera, ' Obusa- 
jisaji," (Ecophylla, Paltotkyreus), 97, 
108, 207, 276-84 

enemies of, 172, 185, 282 
(Antelope), and Trypanosomes (see Bush- 
buck, Keedbuck, Situtunga, Water- 
buck) 
Anthia absent from islands, 307 
Ant lion, and Glossina, 52 
" Anyamberege," 70, 116 
Aphnaeus orcas, 124, 199 
Apodidae, larvae of, 213, 220 
Aponomma laeve, 319 

Aposeme (see also Colouration, aposematic), 
206 

implies unpleasant not necessarily dis- 
tasteful quaUty, 207, 213 

must be simple, 206, 235 

combined with procrypsis, 206-7 

displayed when necessary, 206, 210-2 

proved to be of value, 212 

of larva, used by pupa, 216-7 

Lycid, 231-2 

of Planema-Pseudacraea association, 
246-9, 251-3 
Arachnidu, 318-9 

mimetic, 227, 233 
Arctiidae, aposematic, 210-1 

hairy larvae of, 213 
Ardea melanocephala, 158 

purpurea, 156 
Argulus africanus, 321 
Arum, 110 
Asilidae, 316-7 

and Mantidae, 120, 124 

prey of, 54, 97, 317 

poison injected by, 317 
Aslauga purpurascens, 106 
Aspidomorpka, insular abundance of, 120-1 
Atella, 238 
Aterica galene, 102 
Atractocerus brevicornis, 309 
Attitude of caterpillars, 200-1, 214 

terrifying, 221 

importance of, for procrypsis, 196-8 
216 
for mimicry, 227, 311 
Atjsten, E. E., on name " Tse-tse," 19 

Bacilli and Trypanosomes in Glossina, 40, 

41 
Bagshawe, Dr. A. G., 54 
Baker, Dr., 23 
Balceniceps rex, 155 
Balance of nature, 102, 105, 110, 120, 124, 

171, 176. 213-20, 316 
Balantidium, 11 



324 



INDEX 



BdUarica regulorum, 152 

booming noise of, 77 
(" Balwa ") (see Ardea purpurea), 156 
Banda Isle, 89 
Barbatula leucolaima, 167 

Barbel, 194 .,,,„, 

Barbet, scarce on islands, 167 

B\TES, H. W., 195, 205, 225, 229-30, 235, 
281 

Bats, 98, 112,143-4 

Bees, 117, 121,303-4 

prey of Bee-eaters, 1< 2, 23o 

not intrinsically cUstasteful, 207 

Carpenter, (see Xylocopidae), 108 

Rpe-eater 97, 102, 115, 120, 171-3 
food of,' 172, 173,' 218,'235, 237 282, 285 
Drongos & Rollers, interchangeable 
function with, 171, 176 

Beetle, 305-9 ^ . , .^ -.oi 199 
as evidence of insularity, 121, 122 
distasteful to monkey eaten by Boiler, 

218, 306 
mimetic, 231-2, 308-9 
wood-boring, 309 
BELCHER, C. F., 145, 162, 177 
Belenois, 120 

attacked by bu-ds, 237-8 
courtship of, 223 
seasonal forms of, 202 
Belong aster, 284-6 
prey of, 97, 108, 285 
eaten by Bee-eater, 172, 285 
as model, 285, 310, 311 
enemies of, 286 
compared with Fossors, 287 
Bembex, 95, 286, 288-93 
and Glossina, 53, 288-93 
enemies of, 291-293 
capensis, 292-3 
forcipata, 288-92 

ugandensis, 293 . j. mo 

Bird-droppings resembled by insects, 198, 

199, 204, 216 
Birds and fflossiua, 37, 53 . 

of islands, compared with mainland, 145, 

164, 166-7, 171, 173, 17a-7, 1<9 

local races on islands, 275 ^ ,, ,„„ 

iniectivorous, on " Spider islands, 102, 

105, 120, 124 

attacks of, on butterflies, 111, 173, 

208, 225, 235-8. 267-8 
attacks of, on butterflies, selective, 238 
species of, interchangeable function of, 
171, 176 
Bitis arietans, 188 

nasicornis,-Q6, 187-8 
Bittacus, 310 
Blattidae, 314 

hunted by Dorylus, 2^9-80 
(Blind worm) (see Slow Worm) 
Boomslang, 191 
(Bottle-bird) (see Coucal) 
Bracken, 116 
Braconidae, 220 

as models, 233, 307, 308-9 
Lycoid, 232 ^ 

BRUCE, SIR David, 7, 14, 22, 24, 26, 54 

BUBEMBE ISLE, 89, 92 
Bubo lacteus, 163 _ „r r , 

Buffalo and 0. morsitans, 35, 54 
(Buffalo-gnat) (see Simuliidae) 
Buff tip moth, 198 

i^^iLLAK,'l9. 114. 145, 149 166, 180, 
215, 219, 221-2, 283, 308-9 
local races on, 139, 174, 176. 275 
Breeding places of Olossma on. 57 
Pgeudacraea eurytug on, 268-9 



(Bug) (see Eemiptera) 
BUGUYE Isle, 90 
BuLAGO Isle, 94-5, 182-4 

Glossina on, 47 

Breeding place of Olossina on, 69 

butterflies on, 125 
Bul-bul, 105, 117 
Bunaea phaedusa, 201 
BUNYAMA Isle, 89, 93, 143 
(Burnet moth) (see Zygaenidae) 
Bushbuck and T. gambiense, 27 

compared with Situtunga, 133 
BusiRi Isle, 183 

(Bustard) (see Otis) ^ 

Butterflies, attacked by bnds. 111, 173. 
208, 225, 235-8, 267-8 

courtship of, 221-5 , , ^r 

numbers on different islands, 125 

mimetic, less shy in absence of insectiv- 
orous birds, 102 
BuvuMA Isle, size of, 67 

mortality from Sleeping Sickness on, 7-» 
(" Buvumira ") (see Xylocopidae), 303 
Buzzard and Chamteleon, 163 
BwiGGi Isle, 93 
Byblia, 119 

courtship of, 223-4 
Bycanistes suboiUniricus, 168 

an aposematic bird. 302 

cry of. 77, 81 

Caeergates leucosticta, 310 

preys on Olossina, 53, 54 
Camoephaga nigra, attacking ButterHies, 

237 
Cane, 70. 96, 98, 110, 111, 118 
Canoe, description of, and names of parts, 

84-7 
Caprimulgus, cry of. 81, 173 
{Capsidae, mimetic) (see Eolopeltis, Xene- 

tomorpha) 
(Carabidae) (see Anthia) . 

Carpenter, Dr. G. D. H., on inheritance 

of small variations, 241 
(Cassididae) (see AspidomorpM) 
Castalius isis, 119 
Castellani, Dr. -A.. 23 
Caternillar 199 
insular abundance of, 100, 101, 103, 104, 

106, 116 
enemies pf, 101, 172, 220, 288, 316 
instincts of, 200 , , , , 

procryptic, resembbng bird-dropping, 

199- 216 ,. ^ ,, „,. 

rarely becomes aposematic adult, tin 
with special defence, 206 
aposematic, becomes aposematic adult, 
214, 239 ^. , ,. 

if hairy, may become procryptic adult, 
213 
hairy, irritant hairs of, 213-4 

enemies of, 166, 218, 294, 316 
very large, but concealed, 201 
Catopsilia, 120 

Caves, 98, 108 . ^, ■ r-r 

not good breeding places for Gtlossma, 57 

Centipede, large, absent from islands, 319, 

321 
Centropidae, 102, 110, 116, 120, 165-6 

(food of, see Ceuthmochares) 
Cerambycidae, 121, 307-9 

mimetic, 232, 233, 239, 307-9 
(Cercopithecus) (see Monkey) 
Ceroplesis signata, 121 
Ceryle maxima, 169 

rudis, 169 
Cetoniidae, 121, 232 
Ceuthmochares oeneus, 166 



INDEX 



325 



Chagas, Dr., 14 
Chakididae, 51, 52, 220, 313 
Chanipeleon and buzzard, 163 
Charaxes, 97, 103, 106, 11-1 
directive markings, 208 
etheodes, transitional forms, 241 
Chenalopex wgyptiacus, 81, 96, 146, 149 
nest of, 150 
and mongoose, 142 
Chironomidae, 79, 317-8 
food of CEcophylla, 283 
Chrysididae, prey of Bee-eater, 172 
Chrysococcyx, 167 
Chrysomelidae, insular abundance of, 122 

Lycoid, 232 
ChrysophyUum, 98, 215, 259, 263 
Chrysops brucei, 315 
enemies of, 97, 293 
Chrysopsyche varia, cocoon of, 217 

caterpillars of, 200, 216 
Cicada, insular abimdance of, 118 
Cicindelidae, 307 
Ciconia nigra, 155 
Cilix glaucata, 198 
Cirphis, 196 
Clegg, 18, 20 

Climate of islands and mainland compared, 
44, 72 
storms, 73-5 

effect upon G. palpatio, 42-6 
Clouds, 75, 101 
Coccidae, 116 

(Cockroach) (see Blatiidae) 
Coeliaxis carinata, 304 
Coincidence, and detailed mimicry, 234-5, 

310 
Colias, nuptial flight of, 224 
CoUidae, absent from islands, 167 
Colouration, classified, 195 
held to be always concealing, 204, 238 
and habit associated variables, 239 
anticryptic, 203-4 
apatetic, 195, 234 

aposematic (see also Aposeme), 204-6, 
209-16 
and noisy flight, 168 
versus Thayerism, 204-5 
and bold demeanour, 209-12 
proof of value of, 210-2 
and resistance to injury, 212-3, 226 
effect increased by massing, 215 
carried through all stages, 214 
cryptic, 195 
epigamic, 195 
procryptio, 196^202, 312 

combined with special aposeme, 206-7 
general, 196, 199 
special, 196, 197-9, 216 

analogous to mimicry, 234 
effect increased by massing, 216 
pseudaposematic, 229 
pseudosematic, 195 
synaposematic, 230-1 
Concealment of all creatirres, theory of 
(see Longley, Thayer) 
by breaking up large area, 200-1 
(Copper-smith) (see Barbatula) 
Copridae, 305-6 

eaten by Roller, 218 
Conorhinus, 18 
Cook, Dr. A., 7 

Cormorant, 96, 97, 117, 121, 122, 146-8 
nesting places, 147, 158 
robbed by gull, 146 
Cossypha, 178-9 
(Coucal) (see Centropidae) 
Courtship of butterflies, 221-5 
(Crane, crowned) (see Balearica) 



Crayfish, not met with in lake, 320 
Creepers, 72 

make shelter for Glossina pupae, 58, 64 
Crickets, 80 
Crithidia, 12 
Crocisa meripes, 303-4 
Crocodile, 180-2 ■ 

abundance on different islands, 94, 96, 
99, 104, 111-3, 115, 118-9, 122, 
124 

relations with Varanus, 183-5 

as food for O. palpalis, 38, 39, 181 

Trypanosome of, 40 

basking place of, 180 

nest of, 90, 98, 115, 122, 181, 182 
Crotalaria striata, 108 
Crow, 114 
Crustacean, 320-1 

Ostracod, found in gut of Glossina, 42 
Cuckoo, 102, 166, 167 

feeds on hairy caterpillars, 218 

(bronze) (see Chrysococcyx) 
(Cuckoo shrike) (see Campephaga) 
Cuculus solitarius, 166, 167 
CuMjiiNG, Gordon, 20 
Cycle, in life history of Protozoa, 17, 25, 26 
Cynthia cardui, 106 
Cyrtacanthacris, 105, 170, 314 

Bamarius splendidulus , 219 
Damba Isle, 8, 68, 114, 119 

notes on fauna of, 131, 142-3, 145-6, 
158, 165, 176, 188, 197, 200, 227 
279, 280, 283, 315 

Glossina on, 51, 58 

Ps. eurytus on, 256-9 
Danaida chrysippus, 114, 120 

crossing water, 100 

as model, 242-3 

flight of, 243 
Danaida plerippus, flight of, 243 
Danainae (see also Amauris, Danaida) 
103, 114, 120, 125 

as models, 106, 233, 242 

and birds, 225, 235, 238 

toughness of, 213 
Daniels and Newham, ou acute Trypano- 
somiasis, 10 
Darter, 96, 97, 146, 14Y, 148, 158 
Darwin, 18, 224, 225 
Darwinism, and the Mutation theory, 195, 

198, 241, 262, 268-9, 270-2 
Depopulation of islands, a measure against 
Sleeping Sickness, 7, 8, 28 

eft'ect on fauna and flora, 29, 71, 139, 184 
Dermaptera, 314-5, 321 
Dicruriiae, 237 , 

absent from islands, 176 
Dictyophora laticincta, 209-10 
Diloba caeruleoccphala, caterpillar of, 239 
Diploptera, 286 

Diptera (see also Chironomidae, Glossina, 
Simuliidae, Tahanidae), 315-8 

parasitic (see also Jdia, Stylogaster, 
Tachinidae), 294, 302 
Dirphya, 233, 308-9 

Disease, a disturbance of equilibrium, 16 
Distasteful species, reqiiire to advertise, 206 
DiXEY, Dr. F. a., on chance resemblances, 
234 

on Mullerian mimics of second degree, 248 
Dolops ranarum, 321 
Domestic animals and Trypanosoraes, 16 
Dorylus, 97, 186, 276-81 

male comes to light, 80 
Dourine, 14, 18 
Dove, 159 
Dragon fly, 309-10 



326 



INDEX 



Dragon fiy, prey of Bee-eater, 172 

bionomic relations with Glossina, 53-4, 
310 
(Dronco) (see Dicruridae) 
Duck, 149 

Duke, Dr. H. L., 15, 27, 41, 185 
DUTTON, Dr , 6, 23 
DwAji Isle, 319 
DWANGA Mkuutj Isle, 104-5 

butterflies on, 125 
DWANGA Mto Isle, 105-6 

butterflies on, 125 
DwASENDWE Isle, 106-7 

butterflies on, 125 
Dyavodemu Isle, 119-121 

butterflies on, 125 
Dysentery, 11 
njjtisndae, 307 

Eagle (Bateleur) (see Tfc^otarsus) 

(Crested) (see Snizaetus) 

Fish (see also Haliaetiis), 160-1 
(Earwig) (see Fermaptera) 
East Africa, British, Ps. eurytus in, 
245-6, 249, 252-4, 263 

Ex-German, 149, 152, 155, 173, 176, 
238, 282, 302-3, 303 

Portuguese, 9, 283 
Eciton, 281 

(" Egongolo ") (see Millipede), 320 
(" E'gonya ") (see Crocodile), 180 
(Egret) (see Egretta) 

Egretta, 81, 96, 97, 117, 120, 124, 146, 158 
(" E'jansi ") (see Cyrlacanthacris), 105 
" Ekinsambwe," 70, 117, 122 
(" Ekinyira ") (see Flying Fox) 
(" Ekirikiti ") (see Erythrina) 
(" Ekisagazi ") (see Elephant grass)] 
(" Ekisinja ") (see Barbel) 
" E'konkomi," 185 
Elanus cceruleus, 162 
Elephant grass, 105, 117 
Elgon, Mt., Ps. eurytus on, 250 
Elminia longicauda, 175 
Eltringham, Dr. H., 222, 242, 244 
(" E'male ") (see Mud-fish), 79, 193 
" E'mamba ") see Lung-iish), 193 
(" Embata ") (see Goose), 149 
" Embegede," 194 

(" Empavana ") see Ibis, hagedash), 153 
(" Empungu ") (see Eagle, Ush), 160 
(" Empunya ") (see Plover), 152 
(" Endegeya ") (see Weaver bird), 176 
(" Enfuflu ") (see Tortoise), 186 
" Engabi," 138, 183 
(" Engadala ") (see Cormorant), 147 
(" Engali ") (see Crowned Crane), 153 
(" Enga-nga ") (see Horntaill), 168 
(" Enjaba ") (see Crab), 320 
(" Enjobe ") (sec Situtunga), 137 
(" Enkazalugya ") (see Passer), 177 
" Enkeie," 194 

(" Enkobyokobyo ") (see Gull), 146 
(" Enkolokoto ") (see Megaponcra), 282 
('■ Enkonaiuasonko ") (see Stork, open- 
billed), 154 
Enkusa Isle, 108 
(" Ensanafu ") (sec Doryhis), 276 
" Ensenene," 312 
" Ensoga," 104 

(" Ensogwe ") (see Cormorant), 147 
(" Enswa-swa ") (see Varanus), 182 
Entamoeba, 11 

Entebbe, birds at, 164, 167, 171, 175, 
177, 179 

Ps. eurytus at, 250-1, 258-9, 262, 266 
(" E'numba ") (see Belonogaster), 284 
(" E'uunda ") (sec Stork), 155 



(" Envubu ") (see Hippopotamus), 126 
Enyaliopsis, 211 

emits Irritant fluid, 313 
(" Enyange ") (see Egretta), 158 
(" Enyonza ") (see Cossypha), 178 
Ephemeridae, 79, 80 
Ephippigeridae, 313 
Ephippiorhynchus senegalensis, 155 
Epigamic colouration, 195 
Epinephele janira , nuptial flight of, 224 
Epitoxis albicimta and Acraea, 222-3 
Erlangea tomentosa, 107, 113, 117 

attractive to butterflies, 205 
(" Eryato ") (see Canoe), 84 
Erythrina tomentosa, 110, 112, 205 
(" E'salambwa ") (see Bitis), 188 
( E'sami ") (see Chironomidae), 317 
" E'sonko," 322 
(" E'timba ") (sec Python), 188 
•' E'tungulu," 71, 96, 118 
Eucoma atricosta, evidence of insularity, 116 
Euphorbiaceae and Protozoa, 13 
Eupterotidae, caterpillars of, 200, 316 

evidence of insularity, l()3-4 
Euralia, 97, 102, 104, 114, 124 

dinarcha, 103 

dubia, 103, 105, 106 
Mendelian relationship in, 268-9, 272 

Factor, Mendelian, 270, 272 

Fantham and Porter, on Herpetomotuis, 16 

Ferns, 104-7, 115-7 

Fig trees, 71, 113, 115, 117, 159 

Finches (see Friiigillidae) 

Bishop and Widow, absent from islands, 
176-7 
Fireflies, 309 
Fire, spontaneous, 76-7 
Fish (see also E'male, E'mamba), 193-4 

as weather prophets, 78-9 
Fish lice, 320-1 
FiSKE, W. F., 51, 71, 101, 108, 110, 115 

121, 123, 124, 127, 140 
Flagella, 11 

Flagellates, relation with insects, 16 
Flamingoes, absent from Lake, 156 
Fliglit, aposematic, 168, 301-2 

of model and mimic, ^43, 252, 308 
Flowers, 70-2 
Fluid, emitted by distasteful insects, 210, 

211, 231, 313 
Fly beach, 69 

Flycatcher (see also TcMtrea), 96, 97, 102, 
104, 109, 112, 120, 173-5 

niglitingale-like, 107-8, 113, 115, 117, 
121-3 
Flying fox, 143-4 
FORDE, Dr., 23 
Forest, abrupt edge of, 71 
Formicidae, 233 
Fossor, 53, 95, 286-303 

enemies of (see also Idia), 302 

different stages in methods, 286-7 

Lycoid, 232, 293 
FoUNTAlNE, Miss, on Pseudacraea eurytus, 

259 
Fowls, and aposematic grasshopper, 212 
Francolin, forest, 159, 160 

call of, 81 
Fraser, a. D., 54 
Friiigillidae, 177 
Frogs, noises of, 80 

as weather prophets, 78 

Tree, 190 

and snakes, 190-3 
Fryer, J. C. F., 269 
(" Fulungu ") (see Musophaga), 165 
FUMVB Isle, 89, 92 



INDEX 



327 



Gaboon, Pseudacraea eurylus from, 248 
Galactochrysea emini, 146, 160 
(Gamboge tree) (see Haronga) 
Game, Glossina and Trvpanosomes (see 

also Situtunsa), 15, 25, 26, 35 
Game birds, scarce on islands, 159-60 
Gamia biwholzi, 106, 110 
Gecko, absent from islands, 186 
Genet, 142 

Geographical distribution, of models and 
niimics, 235, 241, 247, 250-1, 264, 
262 
Geometridae, caterpillars of, 214, 239 

moths, 199, 233 
GlossiiM (see also Tse-Tse), 81 

geograpliical distribution of genus, 19 
number of species, 19 
life history, 22, 50, 54 
brevipalpis, comes to light, 35 
morsitans, early accounts of, 19-21 
and buffalo, 35, 54 
breeding places, 65 
enemies of, 51 
and Trypanosomes, 9, 23 
palpalis, 21 

distribution of, 9, 24 
numbers of, 30 

and crocodiles, 48-9 
proportions of sexes, 31-2, 45, 47-8 
length of life, 42-4 
effects of climate upon, 42-6 
dependant upon shade, 21, 32-4, 45 
does not cross open water unless 

carried, 34, 48 
birth of larva of, 50 ■ 
emergence from puparium, 22, 52 
time and method of feeding, 34-5, 45 
proved to carry Sleeping Sickness, 2 

4, 7 
no inheritance of Trypanosomes, 25 
duration of infectivity of one fly, 26 
infective in absence of mankind, 42 
breeding places of, first discovered, 54 
characteristics of, 56-60 
ideal, 58, 63 
" Loci," 57 

searched for by female, 56, 63 
destruction of, not possible by only 
clearing breeding grounds, 60 
by artificial breeding grounds, 62-5 
enemies, of larva, 49, 50 
of pupa, 50-2 
of fly, 52-4 
lood of, 36-42 
mammalian, 36 
non-mammalian, 36-9 
vegetable, 41 
water, 42 

endurance of starvation, 42 
larvae and pupae of, requirements of, 
55-60, 62 
resistance to adverse conditions, 46-7 
numbers on different islands, 96-8, 

100, 102-11, 113-8, 120-3 
numbers of pupae on different 
islands, 57, 58, 111, 119, 122 
tachinoides, the only species outside 
Africa, 19 
(Goatsucker) (see Nightiar) 
Gold markings on insects, 199 
(Goose, Egjptian) (see Chenalopex) 
(Pigmy) (see Nettopus) 
(Spur wing) (see Plectropterus) 
Grasshopper, as evidence of insularity, 105, 
110 
aposematic, 209-12, 215 
Gregariousness, increases conspicuousness, 
215 



Gregariousness, rare in procryptic species, 

215-6 
Gull, 78, 81, 117, 145, 146 
Gyrindae, 307 

Haematopota, 97, 315 

Hairs, of caterpillars, 206, 213 

Halcyon chelicuti, 171 

senegalensis (see also Kingfisher), 170 
Haliaetus vocifer, 160-1 

cry of, 78 

and prey, 193 

and Goliath heron, 156-7 
(Hammer head) (see Scopm) 
Haronqa madayascariensi-s, attractive to 

insects, 232, 237, 244, 307 
Heliconinae, 243 
Helotarsus ecaudatus, 164 
Hemiptera (see also Capsidae) 

carrier of disease, 18 

anticryptic, 204 

prey of, 204, 219 

aposematic, 215 

mimetic, 228, 231, 309 

disliked by Dorylus, 280 
Heredity of small variations, 271-2 

in Papiho, 241, 269 
Herodias alba, 146, 158 
Herons, 96, 107, 109, 122, 156-8 

Buff backed, 146, 158, 159 

GoUath, 96, 99, 109, 117, 146, 156-8 
and Fish-eagle, 156-7 

(Great White) (see Herodias) 
Herpetomonas, 12, 13 

of water scorpion pathogenic to mouse, 16 
Hesperidae (see also Andronymus, Gamia, 
RhopalocamjHa), 106, 112, 114, 118, 
120, 125 

prey of Bembex, 288 
Hippopotamus, 95, 110, 112, 118,126-31, 

grazing ground, 98, 130 

noises of, 80, 89, 127 

pathways, 118, 126, 128 

sleeping places, 124, 126, 127 

wallows, 128 
(Hornbill) (see Bycanistes, Lophoceros) 
Humidity, on islands and mainland, 44 

effects upon Glossina, 44, 46 
Hydrochelidon leucoptera, 78, 146 
Hymenoptera, prey of Bee-eaters, 172, 218, 
235, 282, 285 

not always intrinsically distasteful, 207 

parasitic, 220, 313 

syn-aposematic, 231-2 

as models, 233, 308-311 
Hypertely, 196-7 
Hypolimnas misippus, 106 
Hypsidae, 214 

Ibis aethiopica, 154 
hagedash, 97, 146, 153-4 

cry of, 81, 130 
sacred, 96, 99, 146, 154 
Ichneumon flies, 49, 51, 101, 287-8, 297 
Idia, 291-2 
Infusoria, 11 
Insects, as weather prophets, 79-80 

parasitic, 49, 51, 52, 101, 219, 220, 297-8, 

288, 313, 316 
predaceous, prey of, 204, 219, 310 
protected, 217 

enemies of, 218-220, 235, 285, 315 
immunity only relative, 217 
Instinct, limitations of, 200 

in accordance with colouration, 196, 198, 
209, 216, 227, 228, 308 
Insularity, faunal, 100-6, 109, 110, 116-9, 
120-2, 124, 174-5, 275 



328 



INDEX 



Insularity, floral, 105, 107, 108, 110, 113, 

116-7 
Ipomaea, 64, 70, 107, 117, 121 
Irrisorinae, absent from islands, 173 
ISENTWA Isle, 111, 128, l83 

butterflies on, 125 
Islands, 68, 69, 72, 89, 90, 108, 114 

largest, 67 

of Rome and Kerenge groups compared, 
108-9 

derivation of fauna and flora, 109, 119 

smallest on which Glossina breeds, 122 

with monlveys, 131 

with Situtunga, 101, 117, 139-40 

faunal peculiarities (see also Insularity), 
145, 159, 164-7, 171, 173-7, 179, 
237, 304, 319, 321 
Ispidina, 169 

of evil omen, 170 
Ithomiinae, 243 

Jennings, Prof., 272 

JINJA, 126, 161, 162, 164, 167, 171, 175, 

177, 184, 196, 218, 315 
Jordan, Dr. Karl, on Ps. eurytus, 244-5, 

255 

Kagera, R., 67-8, 137 

barrier to Megaponera, 282 
Kakindu, Ps. eurytus at, 274 
" Kala-azar," 13, 16 
Kallima, 221 

(" Kasimagizi ") (see Kingfisher), 169 
Kawaga Islet, 122 
Kerenge Isle, 161, 170, 109-10, 314 

butterflies on, 125 

Sceliphro7i on, 297-8 
KiBiBi Isle, 119, 179, 318 

leopard on, 141 
" Kibo," 70, 105 

KiKUYU Escarpment, P. dardanus on, 271 
(" Kimbala ") (see Heron, Goliath), 156 
KIMMI Isle, 97-9, 182-3, 188, 194, 201 

Glossina on, 32, 47-9, 98 
breeding places for, 58, 60 

Ps. eurytus on, 273-5 

butterflies on, 125 
Kingfisher, 110, 169-71 

cry of, 78 
(" Kirimululu ") (see Chrysococcyx), 167 
KiRUGu Isle, 89 
Kisigalla Isle, 92, 103 

butterflies on, 125 
Kites, 96, 161-3 
Kiuwa Isle, 68, 108, 111-2, 116, 179 

Olossina on, 119 

butterflies on, 113, 125 
Kizima Isle, 95-6, 123, 154, 162, 175, 
179, 182 

butterflies on, 125 
Kleine, Dr., 25 
KolopeUis hergrothi, 309 
KOMB Isle, notes on fauna, 131, 140, 142, 
152, 275, 310 

Ps. eurytus on, 266-8, 274-5 
(" Kunguvu ") (see Tchitrea) 
KuYE Isle, 90 
KYAGWB coast, 167, 176, 245, 251 

Lacertidae, 185 

Lachnocnema bibulus, 109, 1 1 1 
Lamborn, Dr. W. a., 66, 273 
Lamiidae, 121, 233 
Laninrius erytkrogaster, 175 
Laphyima frugiperda, evidence of insu- 
larity, 101 
Larus, 146 
Lasiocampidae, 199, 200, 206, 213, 216 



Lasioeampidae, evidence of insularity, 103 

(Leaf butterfly) (see Kallima) 

Leech, 18 

Leishmania, 13 

Leopard, 141 

Leptaletis forbesi, 233 

(Leptomonas) (see Herpetomo)ms) 

Libythm, 115, 125 

(Lily Trotter) (see Actophilus), 153 

Limenitis, 243 

(Limnotragus) (see Tragelaphus) 

Lipteninae, 107, 233 

Lithosiidae, 232 

Livingstone, 20, 21, 137 

Lizard (see also Gecko), 108, 120-1, 185, 190 

fed upon by G. palpalis, 37 

prey of hawk, 163 
Locustidae (see also Enyaliopsis), 312-4 

enemies of, 163, 294-5 
(Longicorn) (see Cerambycidae) 
LONGLEY, Dr. W. H., theory of coloiu-a- 

tion, 238-9, 301 
Lophocero'i melanoleiwus, 169 
Lukalu Isle, llO-l 

butterflies on, 125 
LuKiusA Isle, 91-2 
LuLA Isle, 104 

faunal characteristics, 316 

butterflies on, 125 
Lung fish, 88, 160, 193 

and Glossina, 39 
(" Lunyonkante ") (see Otis), 153 
Lycaenidae (see also Castalius, Lachnoc- 
nema, Tarucus), 103, 104, 106-8, 
110-4, 117, 120, 124-5, 199, 204 

attacked by birds, 111, 208, 225, 238 

directive markings in, 208 

larva stored by Sphegid, 294 

mimetic, 103, 233 

nuptial flight of, 225 
Lycidae, and mimics, 231-2, 239, 307 
Lymantridae, cater|illlars of, 116, 213, 294 
(Lymexylonidae) (see Atractocerus) 

Madagascar, Pseudacraea on, 242 

(" Ma'ga ") (see Elanus), 162 

" Makindu," 70 

(" Makwanzi ") (see Osprey), 161 

Malacodermidae, 231-2 

Malaria, 11, 17 

" Mai de Cadcras," 14 

Mantidae, 311-2 

on spider islands, 102, 105, 109, 110, 124 

and Asilidae, interchangeable functions, 
120, 124 

enemies of, 172, 203 

anticryptic, 203, 311 
Mantispa, 285, 310, 311 
Marida Isle, 115, 182 

butterflies on, 125 
Markings, directive, 207-9 

terrifying, 220-1 
JLVRSHALL, Dr. C, 54 
Marshall, Dr. G. A. K., on Hornbill, 168 

frog and snake, 192 

seasonal variations, 201, 261 

relative edibility, 217 

Lycoid insects, 231-2 

birds and butterflies, 236 

Mantispa, 311 
Masovwi Isle, 122 
Mastiqophora, 11, 12 
Maungwi; Isle, 107-8, 113 
Megaponera foetens, absent from islands, 

282-3 
Meinertzhagen, Maj. E.., on island 

Situtunga, 92, 139 
Melinda petivcrana, 106, 233 



INDEX 



329 



Melipotia, absent from islands, 304 
Melittophagus mendioimUs (see also Bee- 
eater), 171-8, 237 
Mendelian relationships, Punnctt on, 268-9 
in Ps. eurytus, Poulton on, 263 
and intermediate forms, 269-270 
Merops supercilioxus (see also Bee-eater), 
171-2 
Bionomic relations with OlossiJia, 310 
Mesoplatys ochroptera, 122 
Meteorology, 76, 91 
Methoca, 303 
Mfumbiro Mts., 68 
Millipede, 320 
MiUogramma, 302 
Milvus aegyptius, 162 
Mimacraea poultoni, 103 
Mimicry, 195, 225, 230 
examnles of (see also Ps. eurytus), 227-8, 

231-3, 238, 307-11 
and Natural Selection, 226, 231-5, 266, 

268 
analogous to special procrypsis, 234 
depends upon experimental tasting, 230 
modifications caused by, 228 
imaginary mammalian case, 229 
Mimics, 225 

polymorphic, 242 

occur with models, 228, 250, 251 

numerical relation to models, 226, 229, 

265 
variations in absence of model, 256-9, 

262, 273 
pattern, not species, depends upon 

model, 262-3, 273-5 
may retain ancestral appearance m 

parts not seen, 226-227 
behaviour of, 102, 226, 243, 308 
disregarded by wagtail, 238 
origin by mutation or fluctuation, 241, 
270, 271 
Models, 225 
numerical proportions to mimic, 226, 

266, 267 
behaviour and habits of 226, 238 239, 
243 
Molluscs, 97, 103, 115, 184 321-2 

attacked by Dorylus, 279, 280, 321-2 
Mombasa, Ps. eurytus at, 252-4 
Mongoose, 168 

tricked by goose, 142 
(Monitor) (see Varanus) 
Monkey. 114, 117, 131-7 
on Nkosi Isle, 92 
language, 132-3 
intelligence, 135 
imitativeness, 135 
and Tortoise, 135 

and grasshoppers, mantis, 136, 203 
and alarming inse^^ts, 136, 221 
Mononyx grandicollis, 204 
Moorhen, 111, 117, 122, 153 
Morgan, T. H., 272 
Mosquitoes, 97, 119, 315 
Moth, 196-9, 207, 213-4, 220, 222, 

232-3, 239 
Mtiomu Islet, 121-2 
Mud-flsh, 79, 193 

(" Mujolo ") (see Bee-eater, Kingfisher), 169 
MuLLER, Fritz, 195 

on Common Warning Colours, 229-30 
on Scent Scales, 222 
Muscicapidae (see also Flycatcher), 173-5 
Musophaga rossae, 119, 165 
(Mutation) (see Variation) 
Mutation theory, 239-40 
diflaculties of, 198, 240 
and Darwinism, 198, 262, 268-72 



Mutation, and intermediates, 269-71 
mutations should not retrogress, 241 
does not account for absence of pro- 
cryptic mimics, 240 

Mutilla, 51, 287, 303 

Myriapoda, 319-20 

Myrmarachne Joenissex, 233, 227-8 

(" Nabubi ") (see spider), 318 
" Nagana," 9, 14, 18, 20, 21 

compared with Sleeping Sickness, 24, 25 
(" Nakibengeyi ") (see Fire), 77 
" Namugoya," 190 
Natal, Ps. eurytus in 245-6, 249, 254, 

259 262—3 
Neave, Dr. sTa., 247-52 
(Nectarhiiidae) (see Sun-bird) 
Nepa cinerea, protozoal parasite of, patho- 
genic to mouse, 16 
Nephila, numbers of, on islands, 102, 103, 

105, 107, 109-23, 318 
Neptidopsis, 114 
NeiHis, 105-6, 114 
Nest, Ant's, 227, 276, 282 

Birds', 107, 150, 158, 161, 174 

Crocodile's, 90, 98, 115, 122, 181-2 

Fish's, 194 

Fossor's,- 288-90, 294-7 

Varanus', 98, 118, 183 

Wasp's, 284-6 
Nettopus auritus, 150 

Neuro-muscular system, modifications of, 
in deceptive resemblance, 196-8, 
226-8 
Neuroptera, 309-11 
Nga:\iba Isle, 99-100, 143, 180-1, 188 

Olossina on, 47, 100 

butterflies on, 125 

Ps. eurytus on, 273-5 

Situtunga on, 140 
(Nightjar) (see Caprimulgus) 
Nile, R., 67-8 
Nkosi Isle, 90-92, 131 
Noctuidae, 101, 207 
{Notodontidae) (see Scalmicauda) 
NSADZi Isle, 100-1, 204, 288, 307 

Olossina on, 44 

breeding places of, 56 

Situtunga on, 28-9 
Nuptial flight of butterflies, 224-5 
Nyasaland, Trypanosomiasis in, 9 

Ps. eurytus in, 246, 249, 254 
Nymphalinae (see also Pseudacraea), 103-6, 
110-2, 114, 116, 120, 125, 242 

as mimics, 233 

courtship and nuptial flight of, 223-5 

attacked by birds, 225 

(" Obuduli ") (see Shrimp), 320 

" Obusaji-saji," 100, 283-4 

(" Obutwa-twa ") (see Erlangea), 107 

Odynerus, 286 

Qir.ophylla smnragdina, 100, 283 

mimics of, 233, 227-8 
(Oedicnemus) (see Stone Curlew) 
" Oluzibaziba," 58, 70, 95, 117, 121, 122 

food of Situtunga, 99, 138 
(" Oniugalati ") (see Chrysopkyllum), 98 
" Omukene," 194 
" Omukoba," 99 
" Omukwakula," 105 
" Omululu," 99 
" Omusali," 95 

(" Omusenene ") (see Podo:arpus), 115 
(" Omusoke ") (see Waterspout), 75 
(" Omutimwa ") (see Stone Curlew), 150 
" Omuvuvumye," 70, 122 
" Omuziru," 99 



330 



INDEX 



Onomatopoeia, 152-3, 166-168, 173, 303 

Ophiderea, 207 

Orthoptera, 311-4 

OsnoRN, Prof. H. F., 19 

Osprey, 161 

Otis melanoyaster, 153 

Otter, 140-1 

Owl, 81, 163-4 

Pachnoda sinuata, 121 

pactolicus, 239 

Palm, 70, 105 

Paltothyreus tarsatus, 50, 172, 281-2 

Papilionidae, 98, 106, 125 

directive markings in, 208 

as mimics, 233, 238 
Papilio dardanus, 114 
form diomjms, 273 
hippocoon, 222, 273 
trimeni, 271 
variation in absence of model, 273 
transitional variations, 269, 271 
heredity of small variations, 241 
(? deceived by mimicry, 221-2 
S ? are pseudaposematic, 240 
nuptial flight, 225 

caterpillars resemble bird-droppings 
199 

demodocus, 120 

leonidas, 106, 114, 233 

polytes, 269 

rklleyanus, 238 

umndce, 114 
Papyrus, 69, 117, 118 
(Paradise flycatcher) (see TcMtrea) 
Parle land, 68, 119 
Parrot, 81, 92, 102, 164 
Passer (/rUeus, 177 
Passeriformes, 173 
Pasteur, 21, 220 
Pelican, 149 

Penfatomodiae (see also Damarius), 215 
Pentiki, 104 

Phalacrocorax africanus (see Cormorant) 
147 

lucidus (see Cormorant), 146 
Phasmidae, 312 
Phrosyne brevicornis, 307 
Phi/mateus viridipes, 212 
Pierinne, 112, 114, 120, 125, 204, 208, 213 

attacked by birds, 225, 237-8 

courtship and nuptial flight of, 223, 224-5 

dry season forms, 202 

mimetic, 226-7 
Pigeon, 103, 159 
Pinacopleryx, 202, 223 
Plaintain eater, 103, 110, 119, 165 
Plaiiema, 98, 206, 235 

boldness of demeanour, 209, 233-9 

resistance to poison, 213 

as models, 233, 242, 245-9, 250-4, 256 

variation in numbers on Kome, 266-7 

on sundry islands, 274-5 

adraHa, 253-4 

agatiice, 245-7, 249, 253, 254 

aganice montana, 95, 205, 253-4, 274 

alcinoe, 95, 114, 205, 274 

epaea, 245, 254 

epaeu parayea, 252. 254, 257, 274 

excisa, 248 

macarista, 97, 114, 205, 247-8, 250, 254, 
256-7, 274-5 

macarista pseudeuryta, 247, 254, 262 

poggei, 105, 114, 250, 254, 256-7, 274 

tellus, 233, 238-9, 251, 254, 257, 274 
Pkitysteira jacksoni, 175, 275 
Plectropterus gambensiD, 150 
Plover, 81, 150-2 



Plusia, 199 
Podocarpus, 115 
Pomatorrhynchus, 175-6 
PompiUdae, 232, 286-7, 300-2 
aposematic flight of, 301-2 
PONDOLAXD, Ps. eunitus in, 253-4, 245-7 
(PORTER) (see Fantham and Porter) 
PouLTON. Prof. E. B., classification of 
colouring, 195-6, 206, 230, 234 
on limitations of Natural Selection, 197, 

226-7 
on seasonal variation, 202 
on relative edibility, 217 
on enemies of protected insects, 219 
on terrifying marks, 220 
on scent of butterflies, 223 
on same effect produced by different 

means, 231 
on inheritance of small variations, 241 
on flight of Pseudacraea and Limenitis, 

243 
on Mullerian mimicry, 243, 248 
on forms of Ps. eurylus, 249-250 
on relaxation of selection in absence of 

model, 256-0, 262-3, 266. 273 
on Mutation theory versus Darwinism, 

262, 271 
on Drosophila, 272 
on " painting out," 308 
(Pratincole) (see Galactochrysea) 
Precis, seasonal changes of, 201-2 
courtship of, 223-4 
archesia, 111, 120 
clelia. 111, 120 
sesamus, 201 
Problepsis aegretta, 199 
Protomo)mdi)ia, 12 
Protopterus, 39, 88, 160, 193 
Protozoa, classification of, 11 

causing disease, 11 
Pseudacraea, allied to Limenitis, 243 
distastefulness of, 243-4, 263 
distribution of, 242 
flight of, 243 
habits of, 244 
boisduvalli, 114, 233 
deceptor, 242 

eurytus, distribution of, 235, 241, 245 
genital armature of, 255 
life history of, 259-61 
bred families of, 264 
polymorphism of, 244-5, 255, 259, 

261-2 
transitional forms of 241, 245, 247-8. 

252, 254-9, 260-1, 267 
mimicry deceptive, 242-3, 246, 252, 

255, 263 
never mimetic of a cryptic species, 240 
l)artially protected, 262-3 
aposeme of, 246-9, 251-3 
Mendelian relationships, 263 
form eurytus, 244, 245, 247, 251, 253, 
254-5, 262 
the ancestral form. 257 
form hobleyi, 103, 106, 114, 247, 249, 
250-2, 254-7, 262, 274 
a stable form, 264 
a secondary mimic of kuenowi, 248 
flirting with terra, 259 
lorm imitator, 242, 245, 246, 247, 249, 
254-5 
a fi.xed form, 259, 262-3 
life history of, 259 
form impleta. 252 

form obscura, 104, 252, 254-7, 263, 274 
an unstable form, 252, 264 
inefficient mimic, 252 
flirting with terra, 259 



INDEX 



331 



Pseudacraea 'eurtjtus, lorm poggeoides, 250, 
252, 254-5, 257, 262 
form togersi, 249, 252, 253, 254-5, 263 
form terra. 106, 245, 249, 251, 252-7, 
263, 274-5 
an unstable form, 264 
perfection of mimicry, 251 
flirting with hobleyi, 259 
behaviour of, 239 
form tlrikensis, 103, 114, 245, 247, 248-9, 
250, 254, 257, 262, 274 
a stable form, 264 
kuenowi, 245, 248 
lucretia, 104, 106, 114 

flight like that of Neptis, 105 
poggei, flight of, 243 
simulator, 242 
Pseudocreobotra ocellata, 203, 311 
Psychidae, evidence of insularity, 100, 106 
(Puff-adder) (see BUis) 
PuNNETT, Prof. R. C, on " Mimicry in 
Butterflies," 231 
on birds and butterflies, 235 
on Mutation theory versus Darwinism, 

268-9 
on Mendelian heredity and intermediates, 
270-1 
Python, 116, 188-9 
source of food for G. palpaUs, 39 

Quail, 160 

(Eace, insular) (see Islands, faunal pecu- 
liarities) 
Rat, abundant on certain isles, 95, 112, 116 

Trypanosome of, 13, 18 
Rails, 153 

Reedbuck and T. ffambiense, 27 
Resuvu Islet, 97 
Rhodesia, Trypanosomiasis in, 9 

Ps. eurytus scarce In, 245 
Rhodogastria leucoptera, 210-1 
Ehopalocampta chalybe, 103, 106, 114 

forestan, 106 
Ridley, H. N., 283 
Robertson, Miss, 26, 61 
(Robin chat) (see Cossypha) 
Roller, functions interchangeable with 
Bee-eaters, 171 

absent on islands, 167 

eat Copridae, 218, 306 
RuJiFUA Isle, 123-4, 183 

butterflies on, 125 

(Safari ant) (see Dorylus) 

Salamis, 103-6, 114 

SaliUHca egeria, 232 

Salivary glands, of Glossina, Trypanosomes 

in, 17, 26 
Sallicidae, 228, 233 
Salvia, 99. 105, 112, 119 
(Sandpiper) (see Tringoides) 
(Sand wasp) (see Fossor), 286 
Sanga Isle, 101-3, 164, 214 

Glosntia absent from, 34, 102 

butterflies on, 125 
Sarcodina, 11 
Saturnidae, caterpillars of, 199, 201. 213 

terrifying markings of, 220 
Satyrinae, 103, 125, 213 

attacked by birds, 225 

directive markings of, 208 

nuptial flight of, 225 
Sealmicauda niveiplaga, 197 
Sceliphron spirifex, 295-8 
Scent, produced by male butterflies, 222-3 
Schizorhis, 165 
Schizotrypanum cruzi, 14 



Scoliidae, 12 J, 231, 287, 303 

evidence of insularity, 103 
Scopus umliretla, 155-6 
Scorpion, scarce on islands, 321 
Sege Isle, 116 

butterflies on, 125 
Segregation, 270, 272 
(" Sekanyolya ") (see Ardea melanocephala), 

158 
(" Sekoko ") (see Cuculm solitarius), 166 
Selection, Natural, 196, 241, 262 

produces no more than is necessary, 

197, 202, 226-7 
produces same effect by different 

means, 231 
produces more detailed likeness than 

chance can, 234-5 
originates nothine, 231 
and the Mutation theory, 262, 268-9 
of mimic relaxed in absence of model. 
256-9, 262, 266, 273 

Sexual, 209, 221-6 
SELOrs, F. C, 35, 236 
Sematic colouration, 195 
(" Semirindi ") (see Cormorant), 147 
(" Semukutu ") (see Enyaliopsis), 313 
" Semutundu," 194 
Shelford, R. W. C, on flying snake, 189 

on mimetic spider, 227 

on Lycoid insects, 232 
Shrike, 175-6 
Shrimp, 320 

(" Siafu ") (see Dorylus) 
SiDGWICK, A., 199 
Siluridae, 141, 193-4 
Silver, markings, 199, 319 
Simuliidae, 80, 151 
Simulium damnosum, 315 
SiNDiRO Isle, 118, 183 
Situtunga, 88, 91-2, 101, 117, 137-40 

and Trypanosomes, 15, 27-9, 41 

and G. palpalis, 28-9, 36, 61 

Meinertzhagen on, 139 

Speke on, 137-8 

swimming powers, 61 

Food of, 99 
(Skipper) (see Hesperidae) 
Sleeping Sickness, confined to tropical 
Africa, 1 

symptoms of, 1-2 

closely allied to animal diseases, 2, 24-5 

earliest account of, 2-5 

enlarged glands in, 6 

first associated with Trypanosome, 6, 23 

spread of, 6-9 

Royal Society Commission on, 7, 23 

cause and carrier of, 7, 23-4 

checked by depopulation, 8 

in absence of G. palpalis, 9 

in W. Africa, 17 

eradication of, 61-5 
Slow worm, 190 
Slugs, 321 

as evidence of insularity, 103, 115 

attacked by Dorylus, 279 
Snails, attacked bv Dorylus, 279 
Snakes, 95-6, 116, 187-93 

danger of, 187 

evolution of poison of, 191-3 

as food of G. jmlpalis, 39, 188 
Snipe, 152 

(" Sombabyuma ") (see Ciconia), 155 
Spalgis pilos, 107 
(Sparrow) (see Passer) 
Speke, J. H., 67, 137, 139 
Spheqidae, 286-7, 294-300 

enemies of, 302 

noise of, when working, 295, 298 



832 



INDEX 



Sphegidae, methods compared with Pom- 
pilidae, 300 

unusual nesting place of, 295 

prey of, 294 

Lycoid, 232 
Sphex margiiiatus, 302 

pelopaeiformis, 295 
Sphinc/omorpha, 221 
Spider (see also Nephila), 120, 318-9 

eaten by Sunbird, 177 

and Dorylus, 279 

anticryptic, 203 

mimetic, 227-8 

stored by Sceliphron, 297 

curious web of, 318-9 
Spider islands, 102, 105, 107, 109, 114-5, 
118, 120, 124 

scarcity of birds on, 102, 103, 105, 120, 
124 

predaceous insects on, 108, 105, 109, 120 
124 
Spines of caterpillars, 213 
Spirochaetes, 18 
Spizdetus coronatus, 164 
Sporozoa, 11 

Starling, glossy, absent from islands, 176 
(Stick insect) (see Phasmidae) 
• Stilt, 152 
(Sthik ant) (see PaUothpreus) 
Stone Curlew, 97, 160-1 
Stork, 146, 155 

Common, 155 

(open bil'.ed) (see Anastomus) 

(saddle billed) (see Epkippiorhynchus) 

(whale headed) (see Balaeniceps) 
Storm, 73-5, 82-3, 91-2, 101, 123 
Stylogaster and Eciton, 281 
Sunbird, 103, 105, 111-3, 115, 121-2, 124 

caught in web of Nephila, 109 
Sunflower, 70, 122 
Surra, 14, 18 
Swallow, 108, 113, 117 
SWYNNERTON, C. F. M., ou blrds and 
butterflies, 236-7 

on relative edibility, 217 
(Syntomidae (see Epitoxis) 
Syntomosphi/rum glossince, 51-2 

Tabanidae (see also Chrysops, Tabanus), 

carriers of Trypanosomes, 18 
Tabanus thoracinus, 293 

variabilis, 315 

variatus, 97 
Tachinidae, 220, 286, 288, 297-8, 315, 316 
Tarucus telicanus. 111, 121, 124 
Tasting, experimental, 212-3 
Tavu isle, 96-7, 180, 182-4, 189 

Glossina on, 32, 47-9 
breeding places of, 55 

butterflies on, 125 
Tchitrea emini. 102, 103, 105, 110, 115 116 
124, 171,174 

local island races of, 275 

nest of, 174 
Tdipna nyanzfp, 233 
Teracolu^, 114 

seasonal forms of, 202 

bricht colours of, 208-9 
Terias, 114 

colouration of, 204 

attacked by bee-e<atcr, 173, 237 
Termites. 80, 97, 162 

absent from some 'slands, 96, 112 

prey of Megavonpra, 283 
(Tern) (-(ce Ihidronhelidon) 
TiiAYER, A. H., on colouration, 204, 238 
Thrush, 112, 119, 179 
Ticks, scarce on islands, 319 



Tiger moth, 213 

Tipulidae. 310 

ToKwi Isle, 121-2 

Tortoise, 39, 135, 186 

( Tragelaphus spekei) (see Situtunga) 

Trees (see also '" Ekirikisi," Fig-tree, Podo 

carpus\ 70, 72, 95, 98-9, 104-5 
Trilncha obliquissima, caternillar of, 215-6 
Trimen, n.. 195, 245, 253 " 
Thing mu«eum. Ps. eurylus in, 246, 249 

253-4 
Tringoides hypoleucos , 146, 151 
Trypanoplasma, 12, 13 
Trypanosoma, 12-14 
brucei, 14, 16 
becomes rhodesiense by mutation, 17 
believed to be mechanically trans- 
mitted, 23, 25 
carripd by Q. morsitam, 23 
natural hosts of, 26 
equiiium, 14 
eguiperdum, 14 
evansi, 14 
gambiense, 13, 14, 24 

possibly carried by G. warsitans, 9 
and natural hosts, 15, 26-9 
life cycle, 25-6, 40 
still pathogenic on depopulated 
islands, 28 
grayi, 40 
lew! si, 13 
nigerienae, 15, 17 
rhodesiense, 10, 14, 17 
vivax, 13, 40 
Trypanosomes, and Sleeping Sickness, 7, 24 
position in animil kingdom, 11 
near relations, 12 
general appearance, 13 
human, 6, 9, 10, 14, 23 
do not always cause disease, 15 
hosts of, 15-17 
life cycle of, 17, 25, 40 
and bacilli, in gut of fly, 40-1 
carriers of, 18 

compared with Spirochaetes, 18 
and direct inoculation, 23 
no hereditary transmission of, 25 
Trypanosomiasis, human, 2, 23 
in Rra7il, 14, 18 
in Nigeria, 15 
in Rhodesia, 9, 10 
compared with Nagana, 24-5 
acriiiired imranuity in, 17 
Tse-tse (sec also Olossina), in Uganda, 8 

origin of name, 19 
(Tsetse fly disease) (sec " Nagana ") 
(Tufted Umbre) (see Scopus) 
TULLOCH, Lt., 7 
(" Tutuma ") (see Coucal), 166 

Uganda, Ps. eurytus in, 245, 247-8, 250-2, 
254-9, 262-3 
Sleeping Sickness in, 7, 8 
Ukerewe Isle, 67 
Vranothauma, 110 
Usamhaka, Ps. eurytus from, 254 

Van Someren, Dr., 171 
Varanus, 182-5 

as food of 0. palpalis, 37-8 

nesting places, 98, 118, 183 

basking places, 183 

food of, 151, 184-5, 320 

relations with crocodile, 183 

numbers on different isles, 96, 99 
109-113, 115, 116, 118-9, 122, 124 
Variations, continuity in, 270 

geographical, 235, 241, 247, 262 



INDEX 



333 



Variations, heritable fluctuations, 241, 
268, 271-2 
MutationB, 240-1, 268-9, 270-2 
of mimic in absence of model, 256-9, 

262, 267, 273 
seasonal, 201-2 
Transitional forms, in P. dardanus, 
269-71 
absent in P. pohjtes, 269 
in Ps. eurytus, proportions of, in 

different localities, 265 
survive in absence of models (see Ps. 

eurytus), 266, 273 
and Mutation theory, 268-271 
Vertigo, 322 

Victoria Nyan.ta, 67, 69-71 
climate of, 72 
fall in level of, 69 
signs of weather on, 76-80 
sounds of life on, 80-81 
storms on, 73-5, 82-3 
Vinago, 159 
Vitrina, 321 
Viverridae, 141-2 
Vulture, absent from islands, 164 

Wagtail, 121 

attacks on butterflies, 111, 208, 238 
Waitwe Isle, 116, 117 

faunal characteristics, 116 

Glossina on, 117 
(" Waka ") (see Paltothyreus), 281 
Wallace, 195 

on struggle for existence, 218 
Warbler, 102, 178 
Warning colours, 195, 206, 230 
Wasps, 97, 108, 207, 284-6 

prey of Bee-eater, 172 

syn-aposematic, 230, 232 
Waterbuck and T. gambiense, 27 
Water lilies, 69, 101 



(Water scorpion) (see Nepa) 
Waterspout, 75 
Wavuziwa Isle, 115-6 

faunal characteristics, 116 

Olossina on, 115 

butterflies on, 125 
Weather prophets, 77-80 
Weaver birds, 102-3, 108, 111-3, 115, 

117, 120-2, 176 
Weevil, 196 
Wema Isle, 68, 113-5 

Olossina on, 51, 57, 114 

butterflies on, 114, 125 

monkeys on, 131 
West Africa, Ps. eurytus in, 245, 247-8, 

251, 254, 262 
Wiggins, C. a., collection of Ps. eurytus 

255, 259 
Wind (see also storms), 76, 90 
(" Wonzi ") (see Spizaetus), 164 
(Wood hoopoe (see Irrisorinae) 
Woodlice, 321 
Woodpecker, 78 
Wood swallow, 236 
Woolly bear, 213 

Xenetomorpha carpenteri, 228 
Xylocopidae, 303 

Yempata Isle, 117-8 
accessory isle, 117 
Glossina on, 32, 118 
monkeys on, 131 

Zeltus antifaunus, 114 
ZiGUNGA Isle, 113, 116 

faunal characteristics, 113 
ZiRO Isle, 108-9, 141 
Zonocerus elegans, 215 
Zygaenidae, 213, 230, 232 



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UKWIN BROTHEBS, LIMITED 
WOKING AND LONDON