362 



NA TURE 



[/v/;. 1 8, 1886 



without possessing a sovmd basis for classification into 

 genera or species. The mode of reproduction is not 

 sufficiently known to afford a better means for distinction 

 than the other morphological appearances taken alone ; 

 nor can we depend upon physiological action, which is 

 held by many to vary with the change of form according 

 to altered surroundings." We have the authority, how- 

 ever, of Koch and Klein for believing that a Bacillus 

 cannot change its nature, and be converted from a harm- 

 less into a pathogenic form, as asserted by Biichner. 



It is usual no'.v to regard Bacteria, yeasts, and moulds 

 as constituting a class, the Achlorophyllous Thallophytes, 

 divided into three orders : (i) Schisomycetes (Bacteria or 

 fission-fungi) ; (2) Saccharoinycctcs (yeast-fungi) ; (3) 

 Hyphomyceics (mould-fungi). Zopf, who, we learn, has 

 warmly supported the pleomorphism of Bacteria, has 

 suggested, as a result of his investigations, a division of 

 the Schizoinycetes into the following four groups: (i) 

 Coccacece ; {1) Bacteriacea ; {"^ Lcptotln-ichea; {/^ Clado- 

 thfkhe(e. This classification is adopted by the author, 

 but only as a provisional arrangement, pending increase 

 in knowledge. " In determining," he writes, "the dis- 

 tinctions into species, we must take into account, not 

 only microscopical appearances of the micro-organisms 

 themselves, and their physiological actions, but the cha- 

 racter of their colonies in plate cultivations, under a low 

 power of the microscope, and the macroscopical appear- 

 ances displayed in the various nutrient media. In this 

 way, by considering each individual characteristic, Koch 

 showed that the comma-bacillus of Finkler was a different 

 organism from the Bacillus which was present in Asiatic 

 cholera." 



Group I., the Coccacece, are divided into five genera. 

 Genus i, Streptococcus (chain-cocci), includes the cocci 

 found singly or in chains in acute abscesses ; the cocci 

 occurring in chains in the Jjmphatic channels of human 

 erysipelatous skin, and in the fluid of erysipelatous bullK, 

 which produce typical erysipelas when re-inoculated in 

 man and animals ; cocci found in diphtheritic mem- 

 branes and the surrounding tissues, and described as 

 characteristic of this disease (but a Bacillus and a Bac- 

 terium have also been described as the specific micro- 

 organisms of diphtheria! ; cocci of vaccine lymph, of 

 which they are regarded as the active principle, since 

 filtration deprives the latter of its infectious element, and 

 successful vaccination has been stated to result from 

 artificial cultivations. Numerous other forms are also 

 included in this genus. Genus 2, Mcfismopedia (plate- 

 cocci), includes Coccus gonorrhcea: and Micrococcus tetra- 

 goiius, pathogenic to mice. Genus 3, Sarcbia (packet- 

 cocci), includes Sarcina ventriculi, a coccus occurring in 

 the stomach of man and animals ; Sarcina lutca, a non- 

 pathogenic form ; and some other forms. Genus 4 

 Micrococcus (mass-cocci), includes the coccus of yellow 

 pus, which is also the specific organism of acute infectious 

 osteo-myelitis, a destructive disease of the marrow of 

 bones ; the coccus of blue pus ; the coccus of fowl- 

 cholera ; Micrococcus prodigiosus, a harmless organism 

 which produces a blood-red colour when cultivated on 

 potatoes ; the micrococcus of septicaemia and that of 

 pyasmia in rabbits, and numerous other forms. Genus 5, 

 Ascococcus (pellicle-cocci), only one form known. 



Group II., BacteriacecT, is divided into si.x genera. 



Genus i, Bacterium (cocci and rods, or only rods, which 

 are joined together to form threads ; spore-formation 

 absent or unknown), includes the Bacterium accti which 

 causes the conversion of alcohol into vinegar ; the bac- 

 terium of croupous pneumonia, occurring in pneumonic 

 exudations, which by inoculati n can produce the disease 

 in mice. Genus 2, Spirillum (threads screw-form, made 

 up of rods, or of rods and cocci ; spore-formation absent 

 or unknown). In this genus is contained the spirillum of 

 Asiatic cholera — curved rods or commas, spirilla, and 

 threads. The commas occur isolated or attached to each 

 other, forming S-shaped organisms or longer screw-forms, 

 and are found in the superficial necrosed layer of the 

 intestines, in the mucous flakes and liquid contents of the 

 intestinal canal of cases of Asiatic cholera. They were 

 also detected by Koch in India m a tank used to supply 

 drinking-water. Their development is arrested by de- 

 privation of air, and they are destroyed by drying and 

 various antiseptics. The results of their injection into 

 the duodenums of guinea-pigs, said to have produced 

 choleraic symptoms, have been by others asserted to 

 have been due to septicemic poisoning. The difference 

 in appearance produced by pure cultivations in gelatine- 

 peptone broth of Finkler's comma-bacillus and Koch's 

 cholera-bacillus are very well illustrated, and the differ- 

 ences in growth of these two spirilla in other media care- 

 fully described. Finkler's bacillus or spirillum has been 

 discovered in the evacuations of cases of cholera nostras, 

 and has been shown quite recently to be also pathogenic. 

 In this genus is also contained the spirillum of relapsing 

 fever, observed in the blood of patients suffering from 

 relapsing fever, but present only during the relapses. 

 Monkeys have been successfully inoculated from cases of 

 the disease in man. Genus 3, Leiiconostoc (cocci and 

 rods ; spore-formation present in cocci), contains the 

 frog-spawn fungus, which occurs occasionally in beet-root 

 juice, and the molasses of sugar-makers, forming large 

 gelatinous masses resembling frog-spawn. " The vege- 

 tation is so rapid that 49 hectolitres of molasses, contain- 

 ing 10 per cent, of sugar, were converted within twelve 

 hours into a gelatinous mass ; consequently it is a for- 

 midable enemy to the sugar manufacturers!" Genus 4, 

 Bacillus (cocci and rods, or rods only, forming straight 

 or twisted threads ; spore-formation present either in 

 rods or cocci), includes Bacillus subtilis, the hay-bacillus, 

 occurring widely in air, water, and soil ; Bacillus authracis, 

 or bacillus of splenic fever in cattle, and of woolsorter's 

 disease or malignant pustule in m^n, of which a very full 

 and descriptive account is given, its morphological and 

 biological characteristics having been very completely 

 worked out. This disease, anthrax, is one of those in 

 which Pasteur has succeeded in attenuating the virus so 

 as to produce a "vaccin" capable of conferring immunity 

 on animals after inoculation. The Bacillus tuberculosis 

 also belongs to this genus. The numerous methods of 

 preparing and staining the bacilli are fully described. 

 The bacillus of blue milk, the bacillus of malignant 

 oedema in mice, and that of septicremia in mice, the 

 l^acillus of typhoid fever, observed in inflamed Peyer's 

 glands, in the spleen, mesenteric glands, and the lungs in 

 fatal cases of typhoid fever, but not as yet imparted to 

 animals by inoculation, the bacillus of leprosy, the bacillus 

 of malaria, the bacillus of glanders, and some others,. 



