OF THE MALTESE ISLANDS. 51 



remarkable localisation was in all probability due to the fact that the naval camp 

 was bounded on one side by rocky ground and stone walls, affording excellent 

 breeding-grounds for the flies, while the military camp was remote from such 

 surroundings, and lying fiiUy exposed in the open plain. 



At times also, when Papataci flies were literally swarming in houses near the 

 old bastion at Floriana, not a single individual was discoverable in the city of 

 Valetta, half-a-mile away. In this instance also one may safely infer that the 

 flies at Floriana were breeding in close proximity, and it is highly probable that 

 the actual site was in the interstices between the masonry forming the old 

 fortifications, only a few yards distant from the dwellings. 



The daylight retreats of these flies were often similar to those in which they 

 were found at night, providing always that there was an absence of direct light. 

 Thus in the dwelling-houses and barracks, the flies were found at rest in the dark 

 corners of the rooms, under garments, behind pictures and in other similar 

 places ; but in nearly all cases they occui-red in considerably smaller numbers 

 than at night, though there were one or two noted exceptions. In one instance 

 they could be found in considerable numbers in a badly lighted bedroom at any 

 time of the day, especially after a still, damp night with a heavy sirocco. Odd 

 examples were also found in cellars and in the prison cells in the heart of 

 Valetta : while numbers could be found almost at any time in the small caves or 

 isolated catacombs at Notaliile, and such retreats seemed to be one of their 

 favourite haunts during the day. In the early mornings, shortly after daylight, 

 examples of both sexes may frequently be found inside the mosquito curtains, 

 and after favoiu-able nights they sometimes get entrapped in large numbers by 

 this means. On the slightest disturbance the males may readily effect their 

 escape through the meshes of the net ; but the females, which are generally 

 engorged with blood, are, under such conditions, much more sluggish than at 

 other times and may then be captured with comparative ease, as they cannot 

 escape through the net very readily when the body is distended with food. In 

 one or two instances Papataci flies were dislodged from the interior of stone walls 

 by forcing tobacco smoke into the interstices ; but one met with such little 

 success that this method was abandoned. Sections of the lower portions of 

 stone walls were also covered with chiftbn and carefully examined at intervals 

 during the night, and although the most favourable structures were selected for 

 the purpose, and areas 36 square feet in extent were most carefully covered, not 

 a single fly was entrapped by this method. This is all the more strange seeing 

 that Captain Marett has met with marked success by adopting the plan even on 

 a smaller scale. However this may be, it is perfectly obvious that in the light 

 of Captain Marett's experience stone walls, especially those from which the 

 surface " pointing " has fallen away in patches, leaving free access to the 

 interior, are the frequent, and possibly the principal, resorts of the parent flies. 



Atmospheric conditions have undoubtedly a marked effect upon the flies. On 

 still sirocco nights they take to wing freely and occur in dwellings in larger 

 nmiibers under such conditions than at any other time. On the other hand, 

 when fresh cool breezes are blowing, especially from the north-west, they are 

 rarely seen ; and it is the testimony of everyone who has studied their habits that 



19127 D 2 



