If you look at an anellida you will have to admit that it kind of looks like a tube, from the outside, right.
Well inside the worm has a gut that is just as long and as straight as it is on the...
The body is built on the plan of "a tube within a tube." The inner tube is the straight-line digestive tract, extending from the slit-like mouth on the first segment to the anal slit on the last...