The composition of a minimal medium suitable for the demands of modern genetical work is described. The nutritional requirements of some 15 strains of L. monocytogenes were studied on this medium. DL-6,8-thioctic acid was not essential. The organisms also grew without thiamine but for a convenient colony size this vitamin had to be used. The presence of Fe++, Mg++, and Ca++ ions as well as a low redox potential supplied by thioglycollate was necessary. There was some difference in the amino acid requirements of the strains. The most common demand was for leucine, iso-leucine, valine, and cysteine. The serotype, agglutinability, hemolytic effect, virulence, and nutritional requirements of the Listeria were compared. It seems that these properties are not consistently linked. Two 'EMS' mutants were also studied. The arginine, glutamine, and methionine metabolism of the auxotrophic mutant 025/4/4 was damaged and its virulence was lost. Data connected with the virulence markers of Listeria are discussed.

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The author thinks that the endless and timeless Universe is a permanent substance and energy flow as well as motion of celestial systems and bodies. Celestial bodies may have physical and biological life. Our Earth has both lives which can be divided into different periods of time. Its physical life can mainly be characterized by the atomic evolution, sterility, appearance of water and abiotic chemical reactions. Essence of the biological life is the existence of the living unit. Biological life of our Globe started with the first living unit/microorganism which began to influence on its environment which is a closed system for substance, flora, creature and man but not for hit of celestial bodies and for arrival of different kinds of energy from the space as well as for radiation of heat. The biological life of our Earth can be divided into four parts: before photosynthesis, before mankind, before 1778 and after the industrial revolution.

In our previous publications, we dealt with some general questions connected with biological life and its conditions, the Biosphere as a "closed system" and in our latest paper with the different periods of the Earth's existence (Ralovich Béla), [1]-[6]. In the present article, we show one part of the processes and changes that occurred in our environment during the last 165 years. Performing of our work was difficult because some of the data required are missing and those which were published in single papers frequently differed from each other. It is also a problem that we are neither mathematicians nor physicists. Despite these difficulties, we hope that our efforts will not be fruitless.