KW; The t<outh Aiistniliati Oriiifholoyical Asi^ockitmii. 



AV.A., entitled "Flies on a Sanitary Site and Typhoid in a Boys'" 

 Home:" — "On 9th March, 1920, at about 12 noon, a visit was- 

 paid to a municipal sanitary site where the contents of a 

 number of pans (about SOU) are buried each might. The soil 

 consists ,of pure sand. . . . On the occasion of the visit 

 there was a moderate breeze from the north, the sky was 

 occasionally overcast, and heavy showens were falling at inter- 

 vals. On arriviing at the site it was noticed that a quadri- 

 lateral patch of ground was literally black with Swallows. It 

 was found that this patch of ground corresponded to these 

 trenches the contents of which had been buried from eight to 12 

 days before. On examination of the surface from which the 

 Swallows were turned away, a large number of freshly-hatched 

 flies were seen crawling about. On closer examination nume- 

 rous small holes of a diameter of about two millimetres were 

 seen on the surface of the sand, and it was presumed that these 

 holes were made by the emerging flies. This was easily con- 

 firmed, and in certain situations it was possible to see flies 

 emerging at the rate of several per minute from a patch of 

 sand six inches square. The flies emerged very rapidly ; almost 

 as soon as the frontal sac on the top of tlie emerging fly's head 

 was recognized breaking through the surface, the fly hopped out. 

 The showers of Tain had caused the surface of the sand to 

 "set" tightly, otherwise the channels made by the emerging 

 flies would not have been preserved. The disturbed Swallows 

 returned almost immediately and settled within a few feet of 

 the observer, devouring the flies eagerly. Apparently no other 

 species of birds were availing themselves of the feast. . . . 

 The flies were nearly all house flies (Musca domestica). A 

 few larger "blow" flies were also seen emerging. . . . The 

 countless flies, which hatch out of the excreta trenches are 

 brought there, of course, as eggs or maggots in the pans from 

 the pwunses of the individual householder." It was decided 

 to write to Dr. Dale to ascertain which species of Swallow he 

 referred to. 



The President also mentioned that during his recent trip 

 to New Zealand he had observed the flight of two kinds of 

 Albatrosses — the Wandering Albatross {Diotnedea exulans) 

 and the Black-browed Albatross (Diomedea mclanophryf^) . 

 In starting tlie first impetus Avas obtained by flapping the wings, 

 then the flight is affected by gravity in coming down rapidly 

 to the food in the water, and thirdly by the wind force. He 

 suggested that our next monthly meeting should be jointly 

 with the University Science Club on the subject of "The Flight 

 of Birds," and it was left to him to trv to arrange this meeting- 



