XXViii. ABSTRACT OF PROCEEDINGS, 
comparatively plentiful, and was not found in many parts of the 
continent which were more or less sterile. Infanticide, also prac- 
tised by these tribes, was an effective method of controlling the 
population. As regarded the mutilation of females, he thought 
that from the ignorance of the aborigines about castration, it was 
unlikely that they would understand the more difficult operation 
upon the female. In some tribes, however, the vagina is lacerated. 
The practice of circumcision, and other mutilations of the genitals, 
probably had their origin in ancient rites of an initiatory or 
religious character, and are still carried on in accordance with 
long established custom. 
2. “On a Cordierite-bearing Rock from Broken Hill,” by J. 
Collett Moulden, Assoc. B.S.M., F.G.8. (Communicated by E. F. 
Pittman, Assoc. R.S.M.) 
This is believed to be the first time that cordierite has been 
recorded in Australia. It has asomewhat extensive development 
in the metamorphic rocks of Broken Hill, and is described in 
detail from two parallel exposures of granulitic rock about half 
a mile S.E. by E. from Block 14 Mine. The cordierite occurs in 
large crystals and also in grains through the granulite. A descrip- 
tion of the physical and optical properties of the mineral is given, 
and reference made to the other constituents of the rock, which 
it is decided to name cordierite-granulite. Mention is also gas’ 
of the occurrence of cordierite as a nucleus to the felspar “augen” 
of an augen-gneiss three miles and a half east of Block 14 Mine. 
3. “Note.on the occurre f kelif opal near Tamworth, 
N.S. Wales,” by D. A. Portsr. 
Several years ago, a specimen of opal brought to the writer, was 
"said to have been obtained in the “‘ Never-never” ranges on the 
head waters of Attunga Creek, and not far distant from Mount 
Gulligal, Parish of Attunga, County of Inglis. Some little while 
ago, being in the vicinity, Mr. Porter found the locality and 
secured a few small specimens, one of which he forwarded to 
be exhibited before this Society. The mineral occurs in the 
form of small veins in serpentine rock, and is accompanied by’ 
