VoL. IV. ANN ARBOR, JUNE, 1884. No. 6. 
WHOLE No. 23. 
Original Communications, 
BACTERIA IN DENTINE. 
DR. A. M. ROSS. 
M* attention was attracted by an editorial paragraph on page 
] 90 of the April Microscope that ought not to stand asa 
little matter of scientific news in a scientific journal without 
some correction. 
Little matters are often of very great importance, and if 
little errors creep into reports upon or statements of certain 
scientific facts they should be detected at once. 
It is a popular way of speaking to say ‘* bony structure” of 
a tooth or teeth, and it is often indulged in by those knowing it 
to be erroneous, simply because there is a close resemblance 
between dentine and bone in their constituents—the former 
possessing a small per cent, more earthy matter. The larger 
amount of organic matter possessed by bone being due to blood 
circulation, etc. Buta tooth has no bony structure except the 
covering of the root, and this cementum has no Haversian sys- 
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