PLATE XXIV 
LEEUWENHOEK’S FIGURES OF BACTERIA FROM THE HUMAN MOUTH 
(Letter 39, 17 Sept. 1683) 
Enlarged (X 13) from the engravings published in Arc. Nat. Det., 1695. 
Fig. A, a motile Bacillus. 
Fig. B, Selenomonas sputigena. C....D, the path of its motion. 
Fig. E, Micrococci. 
Fig. F, Leptothrix buccalis. 
Fig. G, A spirocheete—probably “ Spirochaeta buccalis,” the largest form found 
in this situation. 
facing p. 239 
