PARENTAL INSTINCT IN BIRDS. 245 
over their nesting-site. They would choose quiet unfrequented 
nooks. Some would bury their eggs in the sand or under dense 
herbage. 
The instinct which prompts the Turtle to leave its eggs in 
the sand to be hatched by the heat of the sun is in ne point 
inferior to that of the Maleo of Celebes, whose method of nidi- 
fication is precisely the same. This we may take to be a primi- 
tive case, and one where, in order to meet pressure imposed, 
natural selection chose to act on the sagacity of the female 
rather than on the pugnacity of the male. (Cf. p. 247, 1. 18.) 
The Brush-Turkeys (Talegallus) heap fermenting vegetable 
rubbish over their eggs, but show a slight superiority to the 
Maleo, for the male is said to guard the heap, which must 
certainly be a conspicuous object. 
All the females of each polygamous male of primitive birds 
probably laid their eggs together in one large nest. This obtains 
with the Talegallus, Struthio, and others. This habit, like a 
great many other primitive though ingrained remnants of the 
history of evolution, still persists in cropping up as “‘ sports” in 
a variety of birds. Audubon found three females of Meleagris 
gallipavo which had laid eggs in one and the same nest. They 
were sitting on forty-two eggs, so that each bird covered fourteen 
egos. The American Rhea is not averse to making use of a 
neighbour’s burrow in which to lay her eggs, and so with 
Pheasants, Partridges, Wild Duck, and Long-tailed Tits. The 
Game-birds and Plovers, Gulls, &c., sometimes, in thus revert- 
ing, make the mistake of laying their eggs in the nest not of one 
of their own but another species. Such an accident as this was 
undoubtedly the origin of the parasitic habits of the Cuckoo. A 
respectable, homely, and affectionate Cuckoo perhaps impul- 
sively reverted to a nesting trait of her primitive ancestors by 
laying her eggs in the nest of an unsuspecting neighbour. 
When the species had generally commenced this retrogressive 
though luxurious method the nests of other species would have 
to be imposed upon, and so the well-known and parasitic habit 
of the Cuckoo would gradually be evolved. 
Molothrus bonariensis, a parasitic bird, throws an occasional 
“sport.” Several females begin to build an untidy, irregular 
nest of their own, in which they together lay as many as fifteen 
