682 
Birds of Celebes: Megapodidae. 
for it of the needful heat of the sun absorbed during the day by which the 
eggs are kept from perishing in the cool of the night. Now black absorbs heat, 
while white reflects it, and this seems to be the reason why the birds have 
made a chief breeding-spot of the hot black volcanic sand of Wallace Bay. 
It is interesting to note that the black giuvel on these shores alternates with 
white sand, as Meyer knows from personal observation, and that the Moleos 
only select the black as far as is known. A similar observation is made by 
Dr. Studer on Megapodius freycineti in New Britain: here the bird lays its eggs 
in black volcanic sand, the temperature of which registered 38" to 40" C. and 
cooled but little during the night, “as the black sand absorbs very much heat 
and emits little” (Reise der “Gazelle” J 889, III, 253 ; Z. wiss, Zool. 1878, 433). But 
a much more striking display of sagacity in the selection of breeding-spots by 
the Moleo is recorded by the cousins Drs. P. & F. Sarasin, whose words (37) we 
translate: In the Bone valley (ca. 250 m) the naturalists came across “a great 
number of pits, which Maleo-fowls had dug out in order to lay theii' eggs there. 
Our people made a search, and we secured to our satisfaction four new-laid 
eggs. In the same bamboo-thicket, exactly on the spot where the numerous 
Maleo-pits were scraped out, one against the other like Wolf-pits, was a warm 
spring . . . The temperature of the water must have been about 60"C . . . I’he 
circumstance, that here in the mountains, where the temperature e.specially in 
the forest is on the whole low, Maleo-eggs laid simply in the earth should 
come to due development, had puzzled us here already and led us to suspect a 
connection between the situation of these diggings and the warm spring”. 
Somewhat further on their journey up to Bone valley (ca. 300 m) “we struck 
Maleo-diggings again, and just as in the last case we discovered not far from 
them a warm spring of perhaps 50" C, which formed a little brook Although, 
on putting the hand in it a sharp smarting sensation of the skin between the 
fingers resulted, all the stones of the brook there were padded with a blue- 
green alga. With regard, then, to the breeding of the Maleo we believe our- 
selves able to maintain that the bird indeed lays its eggs as a rule in the sand 
on the hot sea-shore, where the heat of the sun then proves pow^erful enough 
to hatch them, but that in the mountains and especially in the shady forest of 
the interior the warmth of the sun must be substituted by something else, and 
that for this purpose the Maleo then chooses the water of Tvarm springs, which 
it searches out, and makes its breeding-pits in the ground warmed by them. 
Accordingly, where Maleos are encountered in the interior of the country, there 
warm springs should be not far otf. 'Ihe Maleo thus makes use of two inor- 
ganic sources of warmth, by which its eggs are to be hatched, namely, on the 
one hand the sun, on the other warm springs*). Of the latter condition we 
found still further confirmation, for near another still hotter spring, in which 
') Other Megapodes make use of the heat produced by the fermentation of vegetable matter placed on 
their eggs. 
