ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 597 



Observations on Egyptian ophthalmia showed that two different 

 diseases are ordinarily included under this name ; one caused by a 

 kind of bacterium resembling the micrococci of gonorrhoea, the other 

 and less severe one by a very minute bacillus. 



The experiments carried on in India determined the presence in 

 the intestines, in all cases of cholera, of the same bacillus as that 

 found in Egypt ; and this Dr. Koch has been able to isolate and to 

 cultivate. It then furnished characters in its form and mode of 

 growth in nutrient gelatine, by which it is at once distinguished with 

 certainty from all other known bacilli. This particular form was also 

 never found in the intestines or in the ejecta of those not suffering 

 from cholera. Experiments on the infection with it of other animals 

 had not, up to the time of the publication of these reports, been 

 completely successful. 



The cholera-bacillus is not quite straight, like most other bacilli, 

 but is somewhat curved, in the manner of a comma, or even nearly 

 semicircular. In cultivation there often arise S-shaped figures, and 

 shorter or longer slightly wavy lines. They are endowed with active 

 spontaneous motion. They can be best observed in a drop of nutrient 

 fluid attached to the cover-glass, which they are seen to swim through 

 in all directions. In gelatine they form colourless colonies, which 

 are at first close and have the appearance of small fragments of 

 glass, but gradually spread through the nutrient fluid. They have a 

 tendency to collect at the margin of the drop, where their peculiar 

 movements can be well observed, and their comma-like form after 

 treatment with anilin-solution. 



As to the question whether their presence is simply due to the 

 presence of the choleraic disease which promotes their growth and 

 development, or whether they are themselves the cause of cholera, 

 Dr. Koch is very strongly of opinion that the latter is the true 

 explanation, since they are never found either in the organs or the 

 ejecta, except in the case of patients who have either died of or are 

 suffering from cholera. They are also found only in that organ 

 which is the seat of the disease, viz. the intestines. In the first 

 feculent ejecta, the bacilli occur only in small quantities ; while in 

 the later liquid odourless ejecta, they occur in enormous quantities, 

 all other kinds of bacteria being almost entirely absent ; they diminish 

 in number as the excreta become more feculent, and have entirely 

 disappeared when the patient is completely restored to health. Their 

 abundance appears to correspond to the degree of inflammation of the 

 mucous membrane of the intestines, attaining their maximum when 

 this is of a bright-red colour, and the contents a colourless odourless 

 fluid. When the C(nitents become offensive from effusion of blood the 

 bacilli decrease in number and are found only in the vesicular glands 

 and their neighbourhood. Where death results from a secondary 

 complaint following cholera, they are altogether wanting. Their 

 behaviour therefore closely resembles that of all other pathogenous 

 bacteria, their development being i)roportional to the severity of the 

 disease. 



