RT Journal Article SR Electronic(1) A1 van Boven, C. P. A. A1 Ensering, Henriette L. A1 Hijmans, W.YR 1968 T1 Size Determination by Phase-contrast Microscopy of the Reproductive Elements of Group A Streptococcal L-Forms JF Microbiology, VO 52 IS 3 SP 413 OP 420 DO https://doi.org/10.1099/00221287-52-3-413 PB Microbiology Society, SN 1465-2080, AB SUMMARY: Slide cultures consisting of small agar blocks were inoculated with the L-forms of two group A streptococci strains gl-8 and aed grown in broth. The size of the L-form elements was measured on photographs taken immediately after inoculation of the slide cultures. The diameter of the elements varied between 0·2 and 3·0 μ. The frequency distribution of the diameters has a bimodal form. This bimodality probably represents the size distribution of two classes of L-form elements which can arbitrarily be divided at the diameter of 0·7 μ. The reproductive elements of the streptococcal L-forms were found, with a few exceptions, to have a minimal diameter of 0·7 μ (average diameter 1·4 and 1·2 μ, respectively; standard deviation 0·3 μ). Slide culture experiments with concentrated filtrates of 0·45 filters showed that the reproductive elements present in the filtrates ranged in size from 0·8 to 1·7 μ with an average diameter of 1·2 μ (standard deviation 0·2 μ). The filterability of the streptococcal L-form might therefore be mainly due to the plasticity of the L-form elements., UL https://www.microbiologyresearch.org/content/journal/micro/10.1099/00221287-52-3-413