ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 573 



only be seen a few dancing granules, but more frequent and characteristic 

 was a further stage of bright flocculent masses apparently made up of 

 tiny amcebula?. In these masses nucleated bodies about the size of 

 red corpuscles made their appearance later— the sporoblasts. These 

 could develop microbes of various kinds. The one almost invariably 

 met with — the sporozoite, in fact — was a bacillus of the subtilis type. 

 This bacillus, in young growths, usually passed on in a few hours to the 

 protist stage without giving any indication of its presence to the naked 

 eye, and the serum again became apparently sterile to subculture. This 

 cycle, with appearance and disappearance of the bacillus, might take 

 place several times, but eventually, with the exhaustion of the medium 

 for the protozoal phases, the bacillus came to stay. It, however, might 

 be present for some days only in small numbers if any of the other stages 

 were present which had not completed their evolution. It then grew, 

 usually as a wrinkled film on the surface, and formed spores. A single 

 cycle appeared in many cases to take about a fortnight, but several 

 overlapping cycles were usually present. 



Other bacteria which had been seen to develop from these sporoblasts 

 were a drumstick bacillus in symbiosis with a coccus. These were seen 

 to emerge from the sporoblasts of a moribund patient after a fortnight's 

 incubation. These latter sporoblasts, subcultured from the serum of a 

 rheumatic case, appeared as a solitary hard colony on agar on the eighth 

 day, the streptococcus developing from them two days later. A staphylo- 

 coccus had also been seen to develop from similar sporoblasts on an 

 agar slope. 



The spores of this subtilis bacillus had been transformed into the 

 protozoal stages by growing them on agar at 60° and then in 10 p.c. 

 unfiltered pepton solution acidulated with metaphosphoric acid at 37° C. 

 The transition to the protist was complete in about twelve hours, when 

 the subcultures were negative. A couple of clays later there appeared 

 the nucleated sporoblasts. Unfortunately, the medium had apparently 

 not been suitable for the repetition of the cycle, and the bacterium 

 which developed from them did not disappear, but grew on and formed 

 spores. 



Every type of bacterium which had been tried — and the attempt 

 had been made with a considerable number of non-pathogenic ones — 

 had been transformed into this subtilis type with more or less ease, 

 usually by growth in broths of varying alkalinity, \ c.crn., 1 c.cm., or 

 more of a 5 p.c. solution of sodium hydrate being added and the cultures 

 kept at the required temperature, the optimum for many being about 

 42°. The cultures passed through the protist stage to the sporoblast, 

 from which the usual sporing bacillus developed. The longest time 

 taken was about four days. Some bacteria changed much more rapidly. 



The bacteria resulting from this transformation resembled each 

 other very closely, both microscopically and in culture, while, on the 

 other hand, a large variety of types of growth could be obtained from 

 each bacterium, by, for example, heating the spores to temperatures not 

 sufficient to kill them. Each bacillus might occur also in a motile and 

 non-motile form. There was shown a motile bacillus turned into a non- 

 motile by growth at 60° in glycerin broth. Non-motile forms, on the 



