STUDY OF FORMS 313 



An examination of the accompanying chronological table 

 will show how the investigations and discoveries in con- 

 nection with ''spontaneous generation," the ''contagium 

 vivum" theory and putrefaction and fermentation must 

 have been mutually suggestive: 



1546. Fracastorius, disease germs theory and direct and 



indirect contagion. 

 1671. Kircher, "contagium vivum" theory. 

 1675. Leeuwenhoek, first saw bacteria, "animalcules." 

 1701. Andry, "animalcules," cause of diseases. 

 1718. Lancisi, "animalcules," cause of malaria. 

 1749. Needham, described development of organisms in 



water around barley grains. 

 1762. Plenciz, arguments for "living cause" theory and 



that "animalcules" cause putrefaction. 

 1768. Bonnet, suggested that probably Needham 's organ- 

 isms came from germs in the liquid. 

 1776. Spallanzani, boiled and sealed infusions. 



1786. Miiller, first classified "animalcules." 



1787. Wollstein, glanders pus infectious. 

 1795-1798. Jenner, vaccination against smallpox. 

 1797. Viborg, transmitted glanders repeatedly. 



1807. Prevost, grain rust, Puccinia graminis. The first 

 instance of a microscopic plant organism shown to 

 he the cause of a disease in a higher plant. 



1810. Appert, directions for "canning." 



1822. Gaspard, infectiousness of material from wounds. 



1834. Renucci, itch— itch mite {Sarcoptes scahiei). 



1835. Paget and Owen, Trichina spiralis. 



1836. Schultze, air through acid to kill "germs." 



1837. Chevreuil and Pasteur, protected meat did not 



putrefy; suggested wound infection due to 



entrance of germs from without. 

 1837. Caignard-Latour, Schwann, alcoholic fermentation 



—yeast. 

 1837. Schwann, air through heated tubes to kill germs. 

 1837. Bassi, muscardine of silkworms, Botrytis hassiana. 



The first instance of a microscopic plant organism 



shown to he the cause of a disease in an animal. 



