10 
The Non-Combed Eyed Siphonaptera 
have been suitable, while on the other the species may have been 
debarred from reaching the district by a mechanical barrier of some 
sort or another. 
The absence of Pulex irritcins from the oases of the Sahara and from 
the Haussa countries south of the Sahara appears to be a well-established 
fact. The German explorers Nachtigall and Rollfs definitely state that 
fleas are absent from these countries, their remarks being corroborated 
by Dr E. Hartert, who also failed to find fleas in the Haussa countries, 
though lice were plentiful. The presence of lice would demonstrate that 
the habits of the natives would permit fleas to thrive, and it is therefore 
not imlikely that the soil and climate are unsuitable to fleas in these 
regions of the earth. These countries, moreover, have for many years 
been in communication with localities where Pulex irritans is known to 
abound. On the other hand the climate and soil of some districts of 
the Ethiopian region appear admirably suited to the human flea. 
Anderson (1856, p. 20), when starting on his expedition in 1850 from 
Walfisch Bay to Lake N’gami, found “ myriads ” of fleas in a deserted 
house formerly inhabited by a trader and situated some three miles 
inland. This statement corroborates what other observers have 
recorded, namely, that the flea propagates in deserted dwellings, the 
adult insect not requiring food to enable it to reproduce its species, at 
least for some time. An observation of a similar character is recorded 
by Euting (1896, p. 11). On an expedition from Damascus inland, 
Euting visited a deserted village and found his clothes on leaving it 
literally covered with fleas. These fleas, he says, appeared in the 
deserted dark rooms of the stone buildings and were apparently 
benumbed and without strength from their long fast. 
In North, South and East Africa where there are European 
settlements, Pulex irritans appears to thrive well, attacking not only 
Europeans but also the natives and wild and domesticated animals. 
Should this parasite have formerly been absent from these countries, 
this fact can only be explained by the assumption of the existence 
of some geographical barrier, or that those tribes of men who came from 
the north and penetrated southwards into Africa lacked the flea. In 
the Oriental Region similar phenomena to those stated exist in respect 
to the distribution of this insect. In those parts of the East where 
European colonies exist and where free intercourse between Europeans 
and Orientals takes place, P. irritans is well established and appeal’s to 
thrive, but it is not known whether this was the case among purely 
native populations prior to the advent of European traders and settlers. 
