Bioinformatics and Functional Genomics, Second Edition

Antony van Leeuwenhoek (1622–1723) has been called the father of protozoology and bacteriology. This figure shows bacteria he observed taken from his own mouth. Figure A indicates a motile Bacillus. Figure B shows Selenomonas sputigena, while C and D show the path of its motion. Figure E shows two micrococci; F shows Leptotrichia buccalis, and G shows a spirochete. He describes these “animalcules,” found in his and others' mouths, in a letter written 17 September 1683. “While I was talking to an old man (who leads a sober life, and never drinks brandy or [smokes] tobacco, and very seldom any wine), my eye fell upon his teeth, which were all coated over; so I asked him when he had last cleaned his mouth? And I got for answer that he'd never washed his mouth in all his life. So I took some spittle out of his mouth and examined it; but I could find in it nought but what I had found in my own and other people's. I also took some of the matter that was lodged between and against his teeth, and mixing it with his own spit, and also with fair water (in which there were no animalcules), I found an unbelievably great company of living animalcules, a-swimming more nimbly than any I had ever seen up to this time. The biggest sort (where of there were a great plenty) bent their body into curves in going forwards, as in Fig. G. Moreover, the other animalcules were in such enormous numbers, that ...