. . The . . 



South Australian Naturalist. 



VOL. IV. ADELAIDE, FEBRUARY, 1923. No. 2. 



FORTHCOMING EXCURSIONS AND LECTURES. 



The list for the year is not vet finalised. Members will 

 receive Proijramme shortly. 



Lectures, "Aquatic Life," November 7, 1922.— The ex- 

 hibits were as follow: — By 'Mr. AV. Rosser, per "Mv. A. H. Elston, 

 larvae of cockshafer beetle and native cockroach. By Mr. 

 R. Carpenter, a species of Ao-onis (myrtle family), the leaves 

 of which ^ive off a strons: eucalyptus odor. By IMr. D. Looker, 

 earbones of the mull away fish and a shore eel from Kangaroo 

 Island. By 'Mr. B. Beck, a large number of native plants col- 

 lected at Mount Remarkable, in illustration of his lecturette 

 on a trip to that district. By Mr. J. K. Fleming, a gorgeous 

 specimen of Eucalyptus macrocarpa, grown by him at FuUar- 

 ton. A lecturette was given by Mr. H. M. Hale, of the S.A. 

 Museum, on "Aquatic Life. " Mr. Hale explained how aquatic 

 animals breathe and their means of locomotion. In speaking 

 of the former the lecturer described the gills or breathing 

 apparatus of fish. Air is present dissolved in water, and fish 

 make use of it by means of their gills, which are highly spe- 

 cialised for this purpose. A fish dies when taken out of 

 water because it cannot breathe the atmospheric air, the gills 

 being only adapted for use in water. Other aqiiatic animals 

 were mentioned such as the axolotl, newt, various Crustacea, 

 yabbie, prawn, larvae of mosquito, dragon fly, water scorpion, 

 drone fly, and green beetle, also water boatmen and others. 

 The breathing organs of each were explained, and it M^as re- 

 markable to note how the various animals adapted themselves 

 to their various modes of living. Mr. Hale next spoke on the 

 modes of locomotion, and referred to fish which have the most 

 highly developed organs for this purpose. Fins were used 

 for balancing and propulsion, and some modifications were pre- 

 sent that acted for defence or attack. Where animals were 

 not entirely of aquatic habits, they developed organs suitable 

 for new conditions or lost them through having lost the use 

 of them. IMr. Hale illustrated his remarks by a fine series of 



