[New data on the karyology of formation of L forms of Proteus vulgaris].

The growth and development of the Proteus vulgaris culture as well as the process of formation of its L-forms were studied following the Pitzurra method on slides covered with an agar layer. The latter were kept upon inoculation in a vertical position in a moist chamber at 37 degrees C. On fixed and stained after Giemza preparations, it was possible to follow the consecutive stages of the cytoplasmic "hernia" formation due to the local disruption of the bacillary cell wall. It was easy to disern the penetration of the nucleoid into this evagination. The growth of the formed cytoplast was followed by multiple reduplication of the nucleoid which ultimately grew out into a scalloped ribbon whose length served to estimate the ploidy of the developing speroplast. Gigantic individuals with massive nuclei were observed. The ploidy of such nuclei could reach 2000--4000 haploid units. The data of light microscopy were confirmed by electronograms of the ultrathin sections of the L-forms of Proteus vulgaris. Frame-by-frame microcinematography of the multiplying Proteus cells grown in the Fonbrun oil chamber and photographed with the aid of the Peshkoff loop-hole objectives has made it possible to register the division of the nuclear apparatus of bacillary forms. On penicillin-containing media, it was easy to observe the formation of the cytoplasmic "hernia", the penetration into it of the nuceloid, and its successive multiplication in the growing cytoplast to form a massive nucleal mass.