702 Mr. Edwin Ashby on the [ Ibis, XXXVIII.— Notes on the Mound-building Birds of Australia, with Particulars of Features peculiar to the Mallee-Fowl, Leipoa ocellata Gould, and a Suggestion as to their Origin.

By Evwin Asusy, M.B.O.U.

We are familiar with the views advanced by several writers that the habit of artificially incubating their eggs, common to the Mound-building Birds of Australia, is a survival from their reptilian ancestors. The following notes suggest an alternative explanation, which the data advanced seem sufliciently to support.

Megapodius reinwardti Dumont. The huge mounds made by the Jungle-Fowl, Megapodius reinwardti, are well known. In 1906 Mr. C. EK. May, who was working on the Government Bore, then testing the shale for coal, at Port Keats, in the Northern Territory, at my request very kindly took the following measurements and supplied me with the notes hereunder :— Nesting-Diameter Circum-Height of | Diameter mound, at base. ference, Mound. at top.

ft. ft, ff.) IMs. ft. Nolet echt D3 167 8 6 sy No. ee. 46 147 78) 12 NouTlo513 33 105 Dba 9 12 Nos TVs 2: 42 132 ta a All the nests were flattened at the top and were more or less covered with brush-wood, which Mr. May thought had been placed there by the birds with the probable purpose of retarding evaporation and thereby keeping the surface-soil of the mound from baking hard. He also suggested that the flattening of the top was due to the frequent digging out of the eggs by the aboriginals.

The mounds are placed in thick jungle, and usually large Tamarind-trees are growing out of them. The Megapode feeds largely on the fruit of the Tamarind, which probably accounts for the consistency with which these trees occur in the mounds, the seeds being excreted by the birds. The same