Original: In moist conditions mats are usually held together by slimy substances secreted by the micro-organisms , and in many cases some of the micro-organisms form tangled webs of filaments which make the mat tougher .
Simplified: In moist conditions mats are usually held together by slimy substances secreted by the micro-organisms .118 ; 1671-7 Some of the micro-organisms form tangled webs of filaments which make the mat tougher .