which obscures all the fine details of its structure. On removal of this dense clothing, slender microscopical differences may be observed in the venation of the wings, the length of the segments of the palps, the number and arrangement of the bristles or spines on the claspers, etc., on which entomologists base a classification, but up to the present there has been little agreement amongst them ; a species has been given more than one name, not only by different entomologists but sometimes by the same.
Grassi^ has studied the life-history of the phlebotomus in Italy, and Marett^ in Malta. It breeds in caves and in the interior of rubble-walls. The eggs hatch in six to nine days after being laid; the larval stage lasts about eight weeks, and as pupae they exist fixed in crevices in fragments of stone for a fortnight. These flies survive in captivity about ten days only, hence great difficulties are encountered in tracing their history. The phlebotomus is widely scattered throughout the tropical and sub-tropical world, and sandflj' fever is almost as broadly expanded.
Franca' states that the phlebotomus occurs at Collares on the coast of Portugal, north of the mouth of the Tagus, in the months of August to October, and reports that sandfly fever j^revails. In the Statistical Report on the Health of the Navy for 1833 we read of an outbreak of 285 cases of summer febricula in H.M. ships anchored in the Tagus.
In Gibraltar the phlebotomus is indigenous. In 1804 sandfly fever was studied by Pym, and there have been annual epidemics ever since, though of recent years the number of cases has been decreasing.
The existence of phlebotonms and of the fever in Corsica has been made known recently by Leger and Seguinaud.^
Langeron'-* finds that the phlebotomus is scattered throughout the south of France.
The sandfly is distributed through the whole of Italy, and is abundant in Kome, Naples and Venice. Numerous writers report the prevalence of the infection in all parts. Tedeschi and Napolitani have made extensive researches in the aetiology of the " summer influenza " of Italy.
In Sicily, Gabbi^" has reported the occurrence of the fever at Catania, Palermo and Partenico. Castro states that it breaks out every year among the troops in Milazzo. The writer captured the phlebotomus at Taormina. They are abundant in places where the disease prevails.
