THE VICTORIAN NATURALIST. 83 



the opening of trenches or other excavations in marshy tracts was 

 in progress there was almost invariably an attack of fever among 

 the white men superintending the work, which was supposed to 

 be due to the freeing of gases from decomposing vegetation. 

 Regarding the suggestion that eucalyptus trees tended to keep 

 away mosquitos he instanced a bungalow in the Niger country 

 which was particularly noticeable for the prevalence of mosquitos, 

 notwithstanding that two eucalypts, E. citriodora, were growing 

 close by the door. 



Mr. T. S. Hall, M.A., drew attention to the valuable work 

 recently published by Mr. F. V. Theobald on this subject, and 

 remarked at the same time on the very limited extent of our 

 knowledge of this group in Victoria. 



NATURAL HISTORY NOTE. 



The hon. secretary read an extract from a letter from Mr. 

 M'Bain, of Point Lonsdale, to Mr. S. A. LeSouef with reference to 

 the spawning of the Murray Cod, Oligorus macquariensis, in 

 which the writer gave it as his experience that the fish spawns 

 about November, when the river, owing to the melting of the 

 snow, is at its highest, and spreads over the flats along its banks, 

 sometimes for miles. Though he had not seen the ova he 

 believes the fish spawn in hollow burnt logs on the flats, where 

 the water is warm, having frequently disturbed the fish in such 

 places, and afterwards seen young fry not more than a quarter of 

 an inch long swimming about in the holes. Directly the water 

 commences to recede the young fry depart and are next found 

 in the main streams in places where there are eddies, and the 

 banks fringed with weeds and long, thin grass ; here they are about 

 an inch long, and if not disturbed will remain in the locality until 

 the next season, when they will be about 4 inches in length. 



EXHIBITS. 



By Mr. A. Coles. — A specimen of the Diving Petrel, Fele- 

 canoides urinatrix, captured on board a steamship in Bass 

 Strait. 



By Miss S. W. L. Cochrane. — Painting of wattles in bloom at 

 Greensborough. 



By Mr. C. French, jun. — Cocoons, pupae, and perfect insects, 

 male and female, of the Bee Moths (Galleria) ; also samples of 

 honeycomb destroyed by these moths. 



By Mr. H. J. Grayson. — Beck's " London microscope " stand, 

 No. 1,129, K^-j with the following note : — " Members interested in 

 microscopical matters will observe that this microscope, though 

 small, is equipped for a considerable range of work, being fur- 

 nished with objectives possessing excellent corrections. The 

 instrument is well made, extremely compact, and probably lower 

 in price than any other microscope of the same capacity hitherto 



