OF THE MALTESE ISLANDS. oo 
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 fully 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 occurred 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 Notabile, 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 favourable 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 chiffon 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 
numbers 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 D2 
