144 THE AUSTRALIAN NATURALIST. 
tember he found some very small larvae about eighteen inches 
beneath the surface in a moist spot. Further search was re- 
warded with about two dozen in all stages, representing all the 
instars except the newly hatched, which is evidently the one 
figured by Sharp. The next instar shows the abdomen consid- 
erably enlarged, and from that on each change brings them a 
little nearer in shape to the fully developed pupa which we find 
crawling out of its tunnel. The eggs are laid in furrows cut 
on the twigs by the female, by means of her powerful anal 
appendages. When hatched, the tiny larvae fall to the ground 
and burrow to a considerable depth where they attach themselves 
to the roots of trees. 
Mr. McCunnocu’s Lrcrure. : 
War IN THE MAnGroves.—The subject of the lecture was the 
Struggle for Existence, as it is to be observed among the ant- 
mals and plants inhabiting a mangrove swamp. ‘The fact of 
the world being already full up was considered, and it was 
pointed out that the myriads of young animals which are con- 
‘stantly being born into it must be introduced to a terrific 
struggle for their lives even at their earliest stages. Those 
that survive must be very few in numbers, the. greater mass 
falling victim to, and providing food for, the others ahready 
established . 
A number of slides illustrated various means and adaptations 
by which inhabitants of mangrove swamps are enabled to take 
advantage of the special conditions found there. These includ- 
ed the caudal breathing apparatus and climbing powers of the 
fish Periophthalmus, which chases small crabs, &c., in the hot 
sun on the mud flats when the tide is out, and even ascends 
into the lower parts of the mangrove trees in search of food. 
Also the grill-like apparatus of the crab, Sesarma, which is able 
to utilise the same water over and over again, and so keep its 
gills moist while it hunts its prey among the branches of the 
trees. A general account of the crocodile and its nest was 
illustrated with photos of actual specimens, while various pic- 
tures of the mangroves themselves gave a general idea of the 
conditions‘ under which they grow. Mbolluses, insects, and other 
groups of animals were dealt with in their turn, while a spe- 
cially interesting set of slides lent by Mr. Baker, Curator of 
the Technological Museum, showed some aboriginals cutting out 
‘their shields from the trunks of the Grey Mangrove, which has 
_ certain qualities to render it especially suitable for the purpose. 
