340 JOURNAL OF SCIENCE, 
Paper—1. “ Notes on the Trochoidal Plane,” by Mr. Law- 
rence Hargrave.-—The paper was explanatory of some models of 
animal progression exhibited by the author at a late exhibition 
of the Society, and gave in detail the opinions and deductions 
he had formed from his observations of the natural motions of 
matter. The author was of opinion that there was evidence to 
show that nature almost universally used the trochoidal plane 
for the transmission of force, and that its use by man opened up 
a wide field. In concluding, he requested the Society to give its 
opinion whether or not there were grounds for believing that the 
trochoided plane was a distinct mechanical power, and if not, 
under what heading the members classed it. Several models 
were exhibited showing how far the authcr had progressed, in 
evolving a machine for universal flight, the model of a bird 
flying being so naturally worked as to evoke general surprise 
and admiration. 
Sydney, September 3rd, 1884.—Mr. H. C. Russell, BA, 
F.R.A.S., President, in the chair. 
New members—Rev. W. Wyatt, B.A., Messrs. S. H. Cox, 
F.G:S,, F.C.S., E. Dowling, J. Gardiner, J’ B: Gibbs, E. J. femzras; 
M.A., M’B.) .&c, T: Kendall, B.A,“ j:-B. ‘Mackenzie, Mitr, 
and A. P. Woods, C.E. 
Paper—“ On a new form of Actinometer,” by Mr. H. C. 
Russell. 
Sydney, 5th November, 1884.—Mr. H. C. Russell, President, 
in the chair. 
New members—Messrs. J. H. Lucas, S. E. Perdriau, C. Ross, 
M.B., C.M., W. C. Williamson, M.D., and A. Yeomans. 
Paper—“ On some mineral localities in the northern district 
of New South Wales,” by Mr. D. A. Porter. 
Professor Liversidge read an extract from a letter received 
from Mr. Caldwell. Writing from Queensland, Mr. Caldwell 
remarks :—“ Ceratodus has interfered with Platypus. The 
Platypus eggs were hatched three weeks ago, and I should have 
been in New England by now, but Ceratodus is much more im- 
portant. Platypus embryos are quite easy to get. I can’t un- 
derstand how they have not been got before. The fact that the 
Monotremes are oviparous is the end of the research for many. 
They don’t understand that it is the fact of the egg having a lot 
of yolk that promises to yield valuable information. Here are 
some of the principal points in the development of Ceratodus as 
observed on the whole embryos. I have not attempted to make 
sections yet; you know what section-cutting is now-a-days. 
The egg measures about 24%4 m.m. diameter, and has the proto- 
plasmic pole darker, as in Amphibia. This egg is surrounded 
by a strong closely investing gelatinous membrane about 3% 
m.m. thick. The segmentation is complete. (Holoblastic). 
Part of the blastopore remains open, and persists as anus, The 
