3* 
study in development of. individual and race; Em¬ 
bryology and Palaeontology combined. There is an 
excellent Chapter on the subject of ’’Heredity" 
in "An Outline of The Universe", Vol. 2,published 
by Penguin Books. Dr. Pearson is at present pre¬ 
paring an interesting exhibit at .the Museum, to 
explain how certain characteristics are transmit¬ 
ted to descendants. Sex, colour, abnormal traits, 
etc. are all determined by the genes in the chr¬ 
omosomes. 
RAT-KANGAROOS . 
One does not hear much about these inter¬ 
esting little animals although they are fairly 
common in most parts of Tasmania. On the main¬ 
land of Australia the y are said to be scarce on 
account of the depredations of the imported fox. 
The Tasmanian Rat-Kangaro.o or Bettong(Bettongia 
cuniculus) is more Kangaroo-like and larger than 
the Tasmanian Dark Rat-Kangaroo or Potoron (Pot- 
orous tridactylus). They both have prehensile 
tails, and use them for carrying nesting material, 
The tail is passed under the body,and the grass, 
being gathered in the mouth is placed in the fo¬ 
re-paws, and thence to the inturned tail. When 
enough has been col3.ected the animal kicks the 
ends into a tidy parcel, grips it with its tail, 
and hops off. The Bsttong favours more open 
country than Potoron. Potorous are common on Mt. 
Wellington. They feed on grasses, roots, and 
underground fungi, and.are very harmless. 
