THE AMERICAN 



MONTHLY 



MICROSCOPICAL JOURNAL 



Vol. X. MAY, 1889. No. 5. 



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Contagious Diseases in Animals.* 



By Professor JAMES LAW, 



ITH.\CA, N. Y. 



The study of contagion to-day is essentially the study of the work of 

 parasites, or minute living beings that subsist on other living beings. 

 The contagious fevers of man and animals are now nearly all demon- 

 strated to be the result of the propagation in the system of the most 

 minute of these living beings, the bacteria. These, as found in the 

 body, are the simplest of all vital organisms, being in the form of sim- 

 ple cells or filaments, straight, bent, or spiral, though they do grow into 

 other forms in diflerent cases when removed from the animal economy. 

 To give an idea of their extreme minuteness, I may say that if 15,000 of 

 the BacterhiJ7i termo were placed end to end they would form a chain 



Description of the Plate. 



Fig. 12. Micrococcus of rinderpest (Russian cattle 



plague) and blood globules. 

 " 13. Diplococcus of swine plague. 

 " 14. Bacillus of swine plague. 



" 15. Bacillus anthracis (from blood of infected 

 guinea pig i and blood globules. 



" 16. Bacillus anthracis (after three hour.'? cul- 

 tivation in broth) and blood globules. 



" 17. Bacillus anthracis forming spores. 



" 18. Bacillus from septicaemia in mouse (two 

 species, large and small) and blood 

 globules. 



" 19. Bacillus tuberculosis and blood globules. 

 " 20. Bacillus tuberculosis, in sigmoid colony, 



from kidney. 

 " 21. Vibrio. 



Fig. I. Micrococcus vaccinae (cow-pox). 



" 2. Streptococcus (spherical bacteria in a 

 chain). 



" 3. Diplococcus (spherical bacteria in pairs). 



" 4. Staphylococcus (spherical bacteria in 

 groups or clusters) 



" 5. Macrococcus monas (large spherical bac- 

 terfum). 



■' 6. Micrococcus urese (infecting inflammation 

 of bladder). 



" 7. Pneumococcus(bacteriaof lobular inflam- 

 mation of the lungs). 



" 8. Micrococcus pa'^tcuri (septicsemia in rab- 

 bit from inoculation with saliva of man). 



" g. Micrococcus of fowl cholera and oval 

 blood globules. 



" 10. Bacterium termo (of ordinary putrefac- 

 tion). 



" II. Micrococcus of lung plague of cattle (con- 

 tagious pleuro-pneumonia) and blood 

 globules. 



22. Spirillum of " surra " (equine relapsing 

 fever) and blood globules. 



This plate has been kindly loaned by Mr. J. S. Woodward, Secretary of the Society. 



* From Tjansactioas of the N. Y. State Agricultural Society. 

 Copyright, 1889, by C. VV. Smiley. 



