ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 453 



Pseudo-tuberculosis.* — Dr. E. Klein makes an important communi- 

 cation on the pathology and aetiology of pseudo-tuberculosis, the disease 

 caused by a microbe first isolated by Pfeiffer in 1889, though the term 

 was applied by Eberth, in 1885, in reference to necrotic caseous nodules 

 found in the viscera of the rabbit and guinea-pig. The microbe has 

 been found by the author in water, in sewage, and in milk. It is patho- 

 genic to guinea-pigs, both by inoculation and by feeding. It gives rise 

 to necrotic caseous foci much resembling the nodules of true tuberculosis, 

 but differing from them in the absence of giant-cells. The bacillus is 

 always present in large numbers in the pseudo-tubercules, and a striking 

 feature is its intracellular distribution. It is cultivable on the usual 

 media, and the growth presents some resemblance to that of B. coli. It 

 differs from the latter in forming alkali, in rendering broth turbid, and 

 in not forming indol. The microbe is a cylindrical rodlet with rounded 

 ends. In some examples one or two flagella were detected by Van 

 Ermengem's method. In gelatin cultures its length varies from 1 ■ 2-2 /x, 

 in agar from 0'8-l /*. Owing to its resemblance to B. coli, doubtful 

 samples from water, sewage, or milk should be tested by experiments on 

 animals. The paper concludes with accounts of experiments on protec- 

 tion in pseudo-tuberculosis, and on the relation of tuberculosis to pseudo- 

 tuberculosis. 



Negative Acid-fast Phase of Tubercle Bacilli, f — Dr. E. Klein re- 

 marks that he has several times come across in milk acid-fast bacilli which 

 were not tubercle bacilli ; and as there are several known bacteria having 

 this acid-fast property, it is unsafe to rely too much on the specific colour 

 reaction. In the incipient stages of growth numbers of tubercle bacilli 

 are anything but acid-fast, for when stained they lose the red and pick 

 up the blue. It is only on young cultures that acid-weak bacilli are 

 found, for after a fortnight few will be met with. The generally accepted 

 view is that the acid-fastness is due to the presence of fat in some part 

 of their anatomy ; but the author suggests that it is more probable that 

 the chemical constitution of the bacillary sheath and the protoplasm is 

 not the same in the several phases of growth on certain artificial media, 

 and that in the earlier stages the bacilli are deficient of that particular 

 ingredient by which they obtain the acid-fast character. 



Production of Casease by a Parasitic Streptothrix4 — Prof. E. 

 Bodin and Prof. C. Lenormand have found that the streptothrix pre- 

 viously described as the Oospora form of the Microsporum of the horse 

 produces in cultures a diastase which, like rennet, coagulates casein, and 

 another diastase which dissolves the clot-like casease. The quantity of 

 casease existing in the culture fluid varies with the nutritive medium 

 and the physiological condition of the fungus. It is greatest in neutral 

 peptonised and glucosed media at the moment when the whole of the 

 glucose is used up, and when the fungus is in the condition of inanition 

 and of dissimilation. It is then that the fungus may be regarded as 

 an active producer of casease. The fluid containing the casease liquefies 



* Local. Govt. Board Rep. 1899-1900 (1901) pp. 355-81 (17 pis.). 



t Tom. cit., pp. 587-92 (2 pis.). 



X Ann. lust Pasteur, xv. (1901) pp. 279-88. 



