336 
Ballot.— Dr. R. S. Rogers, M.A., Adelaide, was elected 
a Fellow. 
Exhibits. — Dr. Verco, several specimens of Atlanta, and 
one of C armaria australis (Quoy & Gaimard), which add two- 
species, two genera, and a new order to the Nucleobranchiata 
of South- Australia. Gihhula coxi (Angas) and G. lehmanni 
(Menke), which had hitherto been confounded. Astele sub- 
granularis (Danker). This, which had been described from 
Bass's Straits, is a half -grown individual of .4. mhcarinatum 
(Swanson). Several examples of Crassatellites ponderosa 
(Gmelin), hitherto known as C. rasfanea, of Reeve, to illus- 
trate differences of shape and weight and colouration. J. G. 
O. Tepper, F.L.S., described a new species of mantis 
(Fischeria quinquelohatus), captured during the N.W. Go- 
vernment expedition, and Phasmides, Lonchodes caurus, 
Cryptocrania corny ta, Acrophylla nuhilosa, A. panJa, Necrosia 
hella, and Bacillus peristhenella, all taken in the same expedi- 
tion. Douglas Mawson, B.Sc, B.E., then gave an address 
on "Theories of the Earth's Origin." Introducing the subject, 
Mr. Maayson stated that the harmonies of the solar system 
proclaim for the individual planets a common origin. Theories 
dealing with the past history of our own planet must, there- 
fore, relate to the others, so that it is necessary, at the outset, 
to be thoroughly acquainted with cosmical geology in all its 
aspects. To this end the physics of the solar system, toge- 
ther with a brief description of the constituent factors, was 
then sjiortly summarised. The nebular theory was pro- 
pounded by Kant, and given mathematical form by Laplace- 
in his "Mechanique Celeste,'' over a century ago. The origi- 
nal theory was later strenuously upheld by Herbert Spencer 
and John Fiske, whose logic failed to disclose its several in- 
accuracies. This theory traces the beginning and develop- 
ment of the solar system from an original gaseous nebula, 
an exceedingly tenuous and intensely heated cloud of matter 
extending in a spheroidal form, beyond the orbit of Neptune, 
the outermost planet. Of late years such serious objections 
have been raised to this theory, that it has been generally dis- 
credited. Sir Norman Lockyer, in 1890, brought forward 
his meteoric hypothesis. Reasoning from his extensive inves- 
tigations in spectrum analysis, he states his views as fol- 
lows : — ^"Nebulae are really swarms of meteorites, or meteoric 
dust in the celestial spaces. The meteorites are sparse, and 
the collisions among them bring about a rise of temperature 
sufficient to render luminous their chief constituents." Pro- 
fessor Chamber liti, of the University of Chicago, has, dur- 
ing the last five or six years, propounded a theory to explain 
the development of the heavenly bodies depending upon 
