468 PROCEEDINGS: BOSTON SOCIETY NATURAL HISTORY. 
In August on the other hand, Scutigerellas are found only beneath 
heavy stones in the moist bed of the stream or deep in the earth in 
shady places, and it is only in such localities that, at that time of the 
year, there is any quantity of moisture in the air. 
One can also prove experimentally their need of a humid atmos¬ 
phere by placing, during a warm day, some specimens in an open 
vessel and others in a closed vessel, the air of which contains water 
vapor. Those exposed to the circulation of the air even though at the 
bottom of a bottle will be likely to die within a short time, while those 
in the humid and unchanging atmosphere can be brought into the 
laboratory unharmed. Too great moisture is disastrous. Specimens 
after capture were kept in Petri dishes with a little earth. When, as some¬ 
times happened, the earth was kept too moist the animals in the wet 
dish died more rapidly than those in drier dishes. They can, however, 
live for some time immersed in clear water without drowning. A 
record for May 9, 1906, states that “an individual has been immersed 
in water under a glass slide for the last three days and is still active.” 
The surface film of water is something that they seem hardly able 
to break through, either from the outside into a drop of water or from 
the inside of the drop to the air. When submerged in water, they 
wander back and forth, stopping each time as the antennae or front of 
head as the case may be, reach the outer film and rarely if ever break¬ 
ing through unaided. It is evident that any animal living in the 
narrow bed of a small water course must often be submerged for a 
time in air spaces beneath small stones at least, if not directly in the 
water itself, so that this endurance of immersion is not entirely un¬ 
expected. 
According to the “Cambridge natural history,” Plateau records 
two Chilopods, Geophilus maritimus and Geophilus submarinus which 
live between tide marks and are able to withstand a submergence of 
from 12 to 70 hours in sea water and of from 6 to 10 days in fresh 
water. 
Though Scutigerella is found in darkness it becomes perfectly 
acclimated to diffuse light and gives no indication of disturbance 
when a covering cloth is removed from the Petri dish. Specimens 
have been kept in saturated air in a tightly corked homoeopathic 
vial for some months with no protection from the light whatever and 
no evil effects were seen. 
