ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 831 



bottle without food, the bacteria were found to have greatly increased 

 in numbers, and were especially abundant in those which were recently 

 dead. Dissections were made for the purpose of ascertaining whether 

 the seeming parasites could be traced to the alimentary canal and in 

 five cases the digestive organs were isolated and crushed. In all these 

 cases the bacteria were very abundant, and could be seen issuing 

 from the stomach in adherent masses, and also in motion separately 

 in all parts of the field. In two cases where a comparison could be 

 made between the contents of the anterior and posterior parts of the 

 canal, they were found much the most numerous in that part of the 

 canal posterior to the Malpighian tubes. The author therefore con- 

 cludes that they have their principal, perhaps exclusive, seat in the 

 alimentary canal. 



Similar experiments made upon chinch bugs taken from the field, 

 gave similar results throughout; but nothing of the sort could be 

 detected in the fluids of the corn-plant louse (Aphis maidis) feeding 

 upon the same stalks, nor in any of a number of insects examined. 



Etiology of Distemper.* — Dr. E. Koch has collected together the 

 literature which records the experiments that have been hitherto made 

 respecting the cause of the distemper (Milzbrand) of cattle, and 

 attempts to settle various disputed points connected with it. 



Koch considers that a frequent source of error in the recorded 

 results is the existence of other infectious complaints, as for example, 

 septicaemia, which present a strong similarity to the distemper, and 

 which are caused by similar bacilli. No certain method of dis- 

 tinguishing these various bacilli has yet been indicated. In opposi- 

 tion to the view of Pasteur that the disease always results from 

 injury to the digestive organs, Koch maintains that infection may be 

 carried from the intestines to other parts of the body when in a 

 normal condition. Buchner's statement j that the bacilli of hay and 

 of distemper can be mutually transformed one into the other, he also 

 regards as resting on insufficient evidence, the requisite care not 

 having been taken to exclude the possibility of the entrance of 

 foreign bacteria into the culture. His own experiments showed that 

 the distemper-bacilli could go through a very large number of genera- 

 tions unchanged, and still retain as great virulence as if they had been 

 just removed from infected blood. 



The author regards Pasteur's assertion, that " the etiology of 

 distemper has been discovered, and with it the prophylaxis of this 

 disease " as premature, many questions regarding it being still 

 undecided. In conclusion, he discusses the question whether the 

 bacilli of this disease can go through their course of development 

 independently of the animal organism. He considers the evidence to 

 be in favour of the conclusion that distemper makes its appearance in 

 localities where dead bodies affected with it have never been buried, 

 and where there is no reason to suppose that infected animals can 



* Koch, E., " Zur Aetiologie des Milzbrandes," Struck's Mittheil. aus d. K. 

 Gesundheitsamte, i. (1881). See Bot Centralbl., x. (1882) p. 289. 

 t See this Journal, ante, pp. 89, 382. 



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