ii6 
The Irish Naturalist, 
May, 
One may begin by noting the eflfects of increasing darkness 
on the landscape and the animals. The dark foliaged trees 
become darker and not distinguishable from black. Where 
these trees cast a shade or appear against a dark rocky ground, 
the intervals between the branches may get quite dark first. 
The dark red coloured cattle get black and may become with 
their darkening colour quite inconspicuous. If they are partly 
white the white shows long after the red disappears in the 
shade of trees ; if the incidence of the light be favourable the 
oxen may be unrecognisable, when a white wall or even white 
sheep show against a dark ground. The incidence of the 
light of course tells. In early morning dark red cattle are not 
at first recognised, nor dark coloured animals, which commonly 
select this time for grazing. The period of rest is, for some 
animalS; the brightest time of the day and as we know, it is 
by no means unusual for animals both wild and tame to 
seek a shady dark place so that the dulness helps more 
than their colour to disguise the mammals or birds, in the 
thickets where they rest. 
A large number of museum birds were taken and viewed 
in bright and dull lights — red and green parrots, woodpeckers, 
kingfishers, jungle-fowl, and others. The colours grew, 
generally speaking, darker, and became black if they 
happened to be of darker hue when beginning the observa- 
tions, but white spots {e.g.^ in Pomatorrhinus) and pale 
yellows and whites were visible as pale or grey spots after their 
recognition was impossible. Pigeons of different colours 
were noted as they appeared when the twilight was advancing 
into darkness. Light lavender owls get pale, but the form 
was not easily recognised. White fantails seemed bright, 
after copper-coloured Jacobins and Archangels were unre- 
cognisable. The darker pigeons became soon inconspicuous 
in the shade. It is evident that the reflection from the leaves 
of trees may contribute to render birds of a complementary 
colour much less conspicuous. 
It becomes impossible to distinguish dull white long before 
white houses or walls are invisible, so that sheep get dull and 
indistinguishable before a white wall or white house is, so that 
in the late evening and early morning the ordinary light is an 
effectual disguise. Sheep prefer the bare places in fields ; in 
