508 
NATURE 
[April 27, 1871 

The plains of S. Africa are characterised by numerous animals 
generally known to the Boers as “ Mierkatjes” (not little 
monkeys as Burchell renders it, but literally ‘‘ant cats ”), Most of 
these are Viverrine Herpestes, Suricates, &c., and all have nearly 
similar habits, Early in the morning these pretty animals may 
be seen in numerous groups sitting up on their hind legs warm- 
ing themselves in the sun, and, when startled, scampering away 
to their holes, with their tails cocked high up in the air. They 
are likewise more or less coloured like the Karoo soil, although 
when individually examined their colours, of course, differ. 
All these feed on mice, small reptiles, and grasshoppers and 
locusts. They likewise greedily devour birds’ eggs. Equally 
common with these in some parts, but especially noticed by me 
near Cradock, is the Xerus setosus Gray, or ground squirrel. It 
is likewise known as a Mierkatje by the Boers. Unlike the 
other Mierkatjes it feeds on small bulbs and tubers called 
“limtjes” by the Boers. Its colour, habits, and long tail, 
cocked up in the air, gives it a striking resemblance to its 
Viverrine neighbours; while in common with them it forms 
burrows in the ground. Of reptiles there is a species of 
Dasypeltis, a snake almost devoid of teeth, very common 
about Algoa Bay, but with whose specific name I am not 
acquainted, When irritated this species coils itself up and darts 
angrily at the intruder, puffing and hissing loudly. When I first 
met with it I was rather cautious in handling it ; but discovering 
its harmlessness I have kept several in confinement. 
A few years ago I was examining some Bushman caves in the 
Nuncazana Valley, Bedford District, when my Hottentot servant 
told me that there was a ‘‘ Groste Nacht-adder ” in the cave, and I 
found what I also took to bea large Night adder. It sprang at us, 
and nearly escaped, On examining it when dead I was much 
surprised to find it was a very fine specimen of my old friend the 
Dasyfeltis, as I had not met with the species since I had left 
Port Elizabeth. Night adders are common in the Nuncazana, as 
also here. On comparing the two snakes I was much struck by 
their general resemblance, although, of course, the Dasypeltis 
has a very dissimilar head; but the curious way it has of blowing 
itself out, and distending its neck, and darting at intruders, 
heightened the resemblance. I cannot help thinking that these 
habits must be serviceable to so harmless a snake. 
In general protective resemblance Reptiles and Batrachians 
offer countless examples, and it is especially noticeable amongst 
the Agamide, one species of which varies throughout the 
eastern part of the colony and Free State. 
With respect to butterflies I need not enlarge, Mr. Trimen 
having done his work most thoroughly. I may mention, generally, 
that Philognoma varanes, when its wings are closed, strikingly 
resembles a dead leaf, and two of its varieties, ¢ and ? P. 
Agathina, are found in forests, and their flight strongly resembles 
falling leaves, as does also that of P. poppea. In his work on the 
“ Rhopalocera”” he mentions the resemblance between the larva 
of Diadema bolina and Danais chrysippus. Amongst birds which 
I have noticed capturing Lepidoptera I may mention that I have 
seen 7chitrea cristata darting at P. Agathina ; Cypselus caffer 1 
have seen take small moths from the grass, and dart at Zerias 
Rahel on our open flats ; AMotacilla capensis I have seen take 
moths and P. hellica; Dnrurus musicus is a voracious bird 
amongst insects, and takes moths, though I cannot state I have 
seen it capture Rhopalocera, yet I think it also attacks Pieride. 
Mantide and some species of flies are, together with spiders, 
I believe, the greatest persecutors of Rhepalocera. One large 
kind of fly pursues Satyride and Tulbaghia meneris, I have 
found a Phasma in the crop of Strix affinis. 
The most perfect cases of mimicry I know of are two spiders 
(specific nature unknown to me) which bear the closest re- 
semblance to ants, They belong to the Sa/ticide, and are, ap- 
parently, related to Salticus formicarius. The one is smooth, 
black, and shining, and runs rapidly on the ground and bark 
of trees, and resembles the ant which builds its nest in Acacia 
horrvida, and is used by the Kafirs for the purposes of torture. 
The other is larger and has its cephalothorax dull black, and 
its abdomen covered with short yellowish hairs. It is generally 
found running on the stems of herbaceous plants and small bushes, 
and closely resembles an ant found in similar situations. The 
fore legs in both species are larger than the second pair, and are 
frequently held up, when they closely resemble the antennze of 
ants, So exceedingly close is the resemblance that, at first sight, 
I have almost always taken them for the imitated ants. 
The most singular cases of protective resemblances in other 
orders are those of Pephricus paradoxus Sparr. ; particularly re- 


marked on in that traveller's work on South Africa ; of another 
Heteropter in my possession apparently allied to the genus 
Phlea, and which I discovered by the greatest fluke, so closely 
did it resemble a knot of the twig on which it was; of two 
species of Phasma, one believed by Mr. Trimen to be Pal/ophus 
Haworthii, Gray, both of which were found in the Karoo on 
dead branches. Acacia horrida, known as the ‘*Doorn Boom,” 
or Mimosa throughout the Eastern province, is a perfect museum 
of protective resemblances. 
I have the larva of a moth, which forms a case so exactly like 
the thorns of that tree that no one could detect it when not in 
motion ; Mr. Trimen will, I hope, determine the species. A 
caterpillar belonging to a geometric moth, which piles the blos- 
soms on its back, and doubles itself up so as exactly to resemble 
the flower heads ; a larva of a species of Meawra, which exactly 
resembles the young thorn leaves on which it feeds, and which 
forms a pupa in a case resembling an excrescence of the bark ; 
an Epeira which has two excrescences on its abdomen exactly 
resembling two old broken thorns. I could recount a number of 
other similar instances, but for the fear of trespassing too much 
on your space. 
Lastly, I would remark how long it often is before frugivorous 
birds discover fruit not indigenous to the country. 
In the drought of 1865 1 was much struck by this. We had a 
solitary damson tree, which had not previously borne much fruit, 
but which that year had abundance. The mousebirds (Coleus) 
and the Red-wing (Jvida moric) had devoured the almond 
and peach blossoms and the figs. With two double-barrelled 
guns we could not keep them from the latter. Meanwhile 
the damson tree was never touched, but ripened its fruit 
beautifully. On the morning of Christmas Day my friend in- 
tended taking them to his sister-in-law. Two hours later there 
was not a damson on the tree; the birds had just found them out, 
and had strewn the ground with their stones. 
Now it has struck me that slight variations in insects may be of 
much greater value than one might at first sight imagine, and such 
would Mr. Weir’s experiments lead one to expect, the birds se- 
lecting certain kinds of dull coloured larvze from amongst others. 
The beautiful instances afforded by the plants and insects I 
have enumerated can surely be only interpreted by Natural 
Selection. There can be no hybridism nor instinctive accumula- 
tion of resemblances in plants or between plants, grasshoppers 
and stones, and why should we go out of the way to call in a 
theory or theories, for which there are no facts as supporters, 
when we have at hand an explanation so much simpler, and 
which readily embraces every case ? 
I have myself no doubt that instinct may come into play, as 
in the case of the thorn imitator, &c. ; and I believe something 
of the kind is noticeable in savage man, in the disguises he uses. 
It is a well-known fact that our soldiers often fired at aloes in 
the Fish River bush, mistaking them for Kafirs, as their red paint 
is an-excellent disguise in the Bush. The North American Indian 
and the Bushmen adopted numerous disguises in hunting their 
prey, or in tracking their enemy, and no one who has not seen 
the latter can appreciate his wonderful power of imitating all 
kinds of animals. 
In conclusion, I may remark that whilst many species of 
Rhopalocera are most abundant in S. Africa, it is very rarely 
that one finds their larvee or pupze. I have been astonished at 
the small success I have had in cases where the imagines are 
most abundant. J. P. MANSEL WEALE 
Brooklyn, near King William’s Town, Kaffraria 
Sexual Selection 
Mr. DARWIN in his recent work on the ‘‘ Descent of Mar. 
has shown that throughout the animal kingdom the male generally 
displays the stronger passions and is always the most eager. The 
males, moreover, whenever secondary sexual characters occur, arg 
as arule, the possessors of weapons for defence or offency, 
brilliant colours, or other ornamental appendages, all of which 
Mr. Darwin supposes to have been acquired through sextal 
selection, either for the purpose of charming the female or for 
struggling with other males for the possession of the femiles. 
In a few exceptional cases among birds, the females ar the 
wooers, and these are then more brilliantly coloured thm the 
males. In Westwood’s work on insects* I met with the/ollow- 
ing passage :—‘‘M. Donzel has published a curious menyir upon 
* fee Introduction to the Modern Classification of Insects,’ Vol. ii. 
P. 33 
