34 
ANIMAL LIFE ON THE 
. It will thus be seen that a continuous flow of water is 
drawn with the speed of a mill race into the creature's 
interior, and after being stripped of its animal matter, is 
ejected on the top with the same force. Turning to the 
mytilis, we observe the same movements going on; and as 
the valves are now considerably widened, we have an 
opportunity of viewing the organs that perform this 
wonderful operation. First we observe a cream-coloured 
belt or band running round the inner edges of the valves; 
this is called the fringe or mantle, and is capable of being 
compressed like the human lips, or extended from both 
sides until it hangs down like a drapery or curtain. It can 
be twisted into any position, or the edges can be brought 
straight together, and an opening or mouth formed in any 
part of the fore-front for the purpose of admitting the 
water in whatever quantity or direction the creature wills. 
Further in, again, hanging from the centre, there are four 
lobe-shaped, dark flesh-coloured valves or organs, which can 
be separated considerably apart, or brought close together 
from the middle to the tips, and another mouth formed at the 
roof between each pair. The outer surface of these organs, 
when minutely inspected, will be seen to be very finely 
corded across the whole length ; and in these cords, which 
are armed with numerous microscopical hair-like appendages, 
scientifically called cilia or eye lashes, lie the secret of the 
creature's wonderful feeding apparatus. When the mouth 
at the mantle is opened for the admission of water, these 
cords are set in motion and revolve, or; as it were, run 
upwards in a chasing fashion like so many little rollers or 
connected parallel shafts, and these acting like buckets, rise 
the water towards the filtering v/eb above, which, rushing 
through, is stripped of its animal particles, and escapes by 
an oval-shaped opening of the outer web through the upper 
