SCORPIONS AND THEIR ANTIQUITY 373 
If such an explanation holds good in the case of the 
scorpions, there is no reason why it should not be equally 
valid in the instance of Pevipatus, It may be objected 
that whereas in the case of the scorpions we have only 
sub-families which occur over such widely sundered areas, 
in Pertpatus we have one and the same genus.* The 
objection would, however, be equally valid if we assumed 
that genus to have attained its present geographical dis- 
tribution by the aid of a southern belt of land, seeing 
that there is no evidence that such belt has existed since 
the end of the Palaeozoic or the commencement of the 
Secondary epoch.f 
Although not coming strictly within the scope of its title, 
this article may be concluded by a brief reference to some 
of the habits of scorpions. All scorpions are nocturnal 
and somewhat sluggish creatures; but while some species 
in which the tail is light carry it stretched nearly straight 
out behind, those in which it is heavier habitually curve 
it over the back; and those forms in which the appendage 
is carried in the latter manner are further distinguished by 
raising their bodies much higher on the legs than is the 
case with the others. Some kinds, again, when walking, 
carry their large pincers stuck out in front of the head to 
act as feelers. All scorpions are carnivorous, while many 
of them, in spite of their sluggish appearance, are able to 
capture and kill such alert creatures as cockroaches. Mr. 
Pocock, who has kept scorpions in captivity, writes that 
“as soon as a cockroach is seized, the use of the scorpion’s 
tail is seen, for this organ is brought rapidly over the 
latter’s back, and the point of the sting thrust into the 
* By some writers Perifatus is split into distinct genera. 
+ There are objections to the theory of an Antarctic continent uniting 
South America, Africa, and Australia, having existed in Tertiary times. 
