". The power to regrow lost parts permits to survive and even to multiply after injury. Three planarians may live and …"

"Feeding. The majority of ns are carnivorous. The smaller fresh-water ones feed upon s and worms that are nearly micro…"

"The s () of s repeat the essentials of kidney form and function, tubules closely associated with blood and body fluid…"

"... s feed upon microorganism from the muck and water of the bottom and in turn are consumed by es, s and mankind."

"... The two problems which face every organism are those of maintaining its own life and continuing its race. Its you…"

"At Kartabo the waters of the meet those of the and soon join the great lake-like flowing north through the low lying …"

"Different waters hold their own special communities; the dainty glen stream shelters companies of in its swift riffle…"

"Among the s and the water weeds of the shallows, lurk es, s, mud minnows, and young . All of these forage upon snails…"

"s are transparent microscopic animals which live in fresh or salt water. They abound in the surface waters of great l…"

"es posses much more beauty and interest than their reputation credits them with. Most of them are marked with conceal…"