by Hans H. Mar­tin — L‑forms are bac­te­r­ial vari­ants with de­fec­tive cell walls and ir­reg­u­lar growth and mul­ti­pli­ca­tion. They arise af­ter pep­ti­do­gly­can, the ex­oskele­ton of the bac­te­r­ial cell wall, has been ei­ther de­graded by bac­te­ri­olytic en­zymes, or its biosyn­the­sis has been dis­turbed by an­tibi­otics and other in­hibitors, or by de­fect mu­ta­tions in es­sen­tial genes for cell wall syn­the­sis. L‑forms with dif­fer­ent de­grees of wall de­fects can arise...