216 MICROBES, FERMENTS, AND MOULDS. 



united in the form of zoogloea, that is agglutinated in 

 small masses ; others, again, in the colourless corpuscles 

 of the blood. .All the organs, and especially the 

 kidneys, were likewise filled with them. 



With the materials gathered at Ludington, Wood 

 and Formad made some experiments in cultures, and 

 were able to inoculate rabbits with croup. These 

 inoculations were made subcutaneously, in the muscles 

 and trachea, and were followed by the production of 

 false membranes, and the animals died with all the 

 symptoms of diphtheria. The blood was full of micro- 

 cocci. An examination of living animals showed that 

 the micrococcus first attacked the colourless corpuscles, 

 within which their vibratile motion could be observed. 

 The corpuscle changed in appearance, the granules dis- 

 appeared, and it became so full of micrococci that they 

 could no longer move : they grew until they caused the 

 rupture of the corpuscle, and then escaped in the form 

 of an irregular mass, which constitutes the zoogloea. 

 Corpuscles filled with micrococci were found in the 

 false membrane ; in the small vessels, which they dilate 

 and completely obliterate ; and even in the marrow of 

 the bones. 



Cultures made in flasks afforded important results. 

 A comparison of the sowings made with micrococci 

 collected at Ludington with those found in the 

 ordinary diphtheritic angina, which is common at Phila- 

 delphia, showed a great difference in the vitality and 

 virulent properties of microbes derived from these two 



