【摘要】 <正> 猪丹毒杆菌和其他细菌一样,有其特异的变异性。这种变异性,随着菌体内在因素与外界环境不同条件的影响和作用,有时表现非常的突出,而其变异情况,可以在自然界或人工培养下于不太长的时间中观察得到。兹将我们几年来观察的初步结果,简要地报告于下,以供有关方面参考并希指正。更多还原

【Abstract】 Through a series of study, it was noted that Erysipelothrix rhusiopathiae, like some other bacteria, exhibited the phenomenon of dissociation, i. e., changes in colony form, culture characteristics, cell morphology, biochemical reactions, immunological reactions and virulence. Dissociation in this particular species of bacteria came into existence by the influence of environmental factors which was evidenced by the fact that under prolonged incubation of bacterial cells on specially-prepared agar plates, there arose from certain colony or colonies the so-called "daughter colonies" or "secondary growths". From each of the respective "daughter colony or colonies", it gave rise in a definite mode to fundamental dissociative types, such as smooth （S）, intermediate （I）, and rough （R） types, as well as some other dissociative types or variants, and at the same time, it occurred the transformation from one type to another types which can be briefly illustrated by the following diagram: Note: S= Smooth colony; I= intermediate colony; R= rough colony. S（s）= Smooth colony with "daughter colony or colonies". I（i）= Intermediate colony with "daughter colony or colonies". R（r）= Rough colony with "daughter colony or colonies". Solid arrow= frequent transformation. Dotted arrow= occasional transformation. Occasionally, however, transformation from one type to another types of colony might be found in certain colonies without any "daughter colonies", such as from smooth （S） type to intermediate （I） type and vice versa, but such phenomenon was uncertain and there were neither any definite ways to be followed nor definite technics to be mastered. It is suggested that if one could get acquainted with the definite mode of dissociation and consider "daughter colonies" or "secondary growths" as the chief resource of bacterial variation and transformation, it would be possible and easy to get various and desirable types of bacterial colony as valuable material for immunological and genetic studies. Besides, it was also observed that as the result of dissociation, certain rough-type colonies （such as R₄ and R₅） possessed the characteristics of recurrent growth-periods so that the alternation of growth and rest resulted with the surface of colony appearing rippled or contoured.更多还原