102 AUSTRALIAN ZOOLOGY, 
the travelling studentship founded in Balfour’s memory He arrived 
in Australia in Sept., 1883, and made Sydney his headquarters. He 
lost some time in ascertaining the best locality for his investigations. 
Towards the middle of April, 1884, he went to the Burnett River, 
Queensland, where he found ornithorhynchus very numerous, so he 
decided to remain in the district till the breeding season was over. 
He obtained the assistance of the blacks, without whose services he 
would have had little chance of success. On Aug. 24th he shot a 
platypus, whose first egg had been laid, at least so he concluded ; 
her second egg was in a perfectly dilated os wtevi. ‘This egg of 
similar appearance, though slightly larger than that of echidna, was 
at a stage equal to a 36-hour chick. On the 2dth he sent the 
following message to Professor Liversidge, of Sydney University :— 
-* Monotremes oviparous, ovum meroblastic,” the last word meaning 
that only a small part of the yolk goes to form the young, while the 
greater part is used to nourish it. Mr, Caldwell requested that this 
intelligence should be forwarded to the British Association at 
Montreal. ‘The young scientist’s black retainers increased to 
upwards of fifty; but it was only occasionally and with great 
difficulty that he could persuade them to dig for platypi; not only 
the blacks but also their dogs refused to eat them. This, his first 
expedition lasted from April to Dec.. during which he obtained 
many of his Monotreme stages, but he found that his camp had not 
been organised on a sufficiently large scale. Mr, Caldwell’s second 
expedition began in June, 1885, he having lost the two previous 
months from the effects of a fever, contracted in the swamps of the 
Burnett River. During July and Aug. he employed over 150 natives. 
In Sept. he transferred the camp to the colder river Mole, further 
south, where he hoped to dig out the latter stages of ornithorhynchus . 
from their nests. e employed some white navvies, who opened up 
a large number, but the renewed exposure in Queensland brought on 
his fever again, he having been previously ill on the Burnett River, 
as mentioned above. ‘This seriously interfered with the completion 
of the ornithorhynchus series. Mr. Caldwell’s proof that the 
platypus lays eggs and ‘‘hatches them out by the warmth of its 
body in the same manner as birds do,” as Mr. Ogilby in_his 
“Catalogue of Australian Mammals” boldly puts it was arrived at 
by a scientific demonstration. How long the supposed period of 
incubation lasts no naturalist has attempted to define. Is it days, 
hours, minutes or seconds? If eggs are laid and all signs of them 
vanish beyond the detection of a scientist, the period of incubation 
must be very brief, and the difference between oviparous and 
ovoviviparous cannot be much. 
LEADBEATER’s Cockatoo—Cacatua leadbeatert. 
Description.—The upper surface of the body, the wings and tail 
are white ; the forehead. front and sides of the neck, the chest down 
to the centre of the abdomen are light rose-colour; the under 
surface of the wings and the basal portions of the inner webs of the 
