On a Parasitical Protophyfe. By G. F. Bowdeswell. 27 



they occur in vast numbers, and may also be recognized in most of 

 the smaller blood-vessels or capillaries. The organism itself is a 

 form of bacillus, the individual cells of which, allowing for foreshorten- 

 ing, are almost exactly 1 micromillimetre (0"001 mm., l-25,000th 

 inch) in length ; that is, just the breadth of some common forms of 

 similar organisms, septic and pathogenic Bacteria, as e. g. the hay- 

 bacillus — B. subtilis of Cohn. Their breadth, by estimation, is 

 certainly less than a fourth of the length, i. e. less than l-100,000th 

 of an inch. To examine and measure these accurately it is neces- 

 sary that the blood containing them should be spread in a very 

 thin layer on the cover -glass, dried and stained. In the tissues, 

 thin and completely decolorized as the section here is, they cannot 

 be sufficiently clearly seen for individual examination. Judging 

 from the relative position and appearance of the cells, it pro- 

 bably possesses a flagellum ; * and no doubt, as other bacilli do, it 

 must form spores, though not perhaps in the tissues of the living 

 animal, where its usual method of multiplication is evidently by 

 fission. These spores would be mere points under the Microscope, 

 circular bodies of only about the fourth or fifth of a micro- 

 millimetre, i. e. less than l-100,000th of an inch in diameter. 



The number in which these organisms may exist in the blood 

 of an infected animal is incalculable ; it may be even infinitely 

 greater than in the case of Davaine's Septicaemia in the rabbit, 

 where, as stated at a previous meeting of this Society,! I found that 

 in some cases one drop of infected blood contained upwards of 

 3000 millions of them. In this case the blood is as infallibly 

 infective as in the other, in the smallest quantities in which it can 

 be taken on the point of a scalpel or a needle. I have not, however, 

 been able to test its infectivity quantitatively, as in the former case, 

 on account of the small size of the animal here, and the blood being 

 invariably much coagulated upon death. It is a remarkable circum- 

 stance and one, I believe, pecuhar to this disease, that the blood of 

 an infected animal during life and within 18 hours, or even less, 

 after inoculation, and previous to the occurrence of any apparent 

 symptoms of disturbance, becomes itself infective, in as small 

 quantities, and in all respects with similar results, as with inocula- 

 tion by the blood of a dead animal. 



* The flagella, if they exist, are probably mere filaments of homogeneous 

 substance : very different from complex independent cells. Many microscopical 

 objects are not distinguishable with our present means unless stained, either on 

 account of their being of the same refractive index as tlie tissues (as in the case 

 of the nuclei of cells), or on account of their minute size (as in the case of this 

 microphyte), and the possible occurrence of others yet unobserved and perhaps 

 unsuspected is suggested by Koch's remarkable discovery of the bacillus of 

 tubercle, which, owing to the chemical reaction of its cell-wall, is not affected by 

 the dyes which were previously supposed to stain all species of the Schizophytes. 



t See this Journal, ii. (1882) p. 310. 



