Appendix. 153 



upon the meat, and he suspected that they were the progenitors 

 of the maggots. In midsummer he took a number of wide-mouthed 

 jars, and placed in them bits of flesh. Some of the jars were left 

 open some were covered with paper carefully secured around the 

 neck. Maggots soon appeared in the open jars, but none were 

 seen in the closed jars, even after weeks had elapsed, while the 

 flesh continued to putrefy just as in the other set. Then using 

 fine gauze as a covering for the jars, the result was the same. 

 His mode of argument, therefore, was, that the cause of the 

 formation of the maggots must be something that is kept away 

 from the meat by the gauze. This something must be solid par- 

 ticles too big to go through the gauze, for air and fluids will 

 readily pass through. Nor can there be any doubt as to what 

 this something is, " for the blow-flies attracted by the odor of the 

 meat, swarm around the vessel, and urged by a powerful, but in 

 this case a misleading instinct, lay eggs out of which maggots are 

 immediately hatched upon the gauze." * 



These experiments were repeated with a great variety of 

 substances, and with various modifications, but the results were 

 uniformly the same, and so far as they went they carried convic- 

 tion ; but it must be remembered that they disproved spontane- 

 ous generation only for the special cases under consideration. 

 The presumption, however, that all instances of the supposed 

 origin of life from dead or inorganic matter might be in a simi- 

 lar manner explained, by the introduction in some way of living 

 germs, rapidly gained ground, and was enunciated by Redi him- 

 self as at least probable. He even suggested that in this way we 

 might explain the generation of the entozoa, or internal parasites 

 of animal bodies. Redi was followed by Swammerdam** and 

 Vallisnieri,*** who repeated his experiments, and the combined 



* HUXLEY : ibidem. 



** JOHANNES: a Dutch physician and entomologist, 1637-1681. He was one 

 of the earliest to make dissections of the human body. He published a num- 

 ber of entomological works. His "History of Insects" was claimed by 

 Boerhaave, his editor, to be incomparably superior to anything that had pre- 

 ceded it. An English .translation was published in 1758. 



*** ANTONIO: an Italian physician and naturalist, 1661-1730. He studied 

 medicine under Malpighi, and was subsequently Professor in the University 



