402 M. Edwards on Spontaneous Generation, — ? 
an 
hat this kind of molecular grouping could be determined by 
inorganic forces in nature. 
€ occurrence of maggots in carrion was one of the cases. 
But since the study of the origin of these animals by the Flor- 
entine Academy, happily named “del Cimento,” and the exact 
investigations, of Redi, one of its members, it has been well 
understood that these worms about dead bodies, far from being 
a result of spontaneous generation, are the brood of well known 
insects, species which find in such bodies the conditions requisite 
for development, and hence, through a marvellous instinct, de- 
which are discernible onl by means of the microscope, ® 
whose germs are so excessively minute that they have é 
all the methods of observation which the science of optics has 
supplied. When, therefore, Lewenhoek and his successors 2 of 
nown the existence of these animalcules, the hypotnems 
Spontaneous generation'regained favor. While some ean 
gists regarded them as derived from germs of extreme minu fine 
which were spread every where in nature, and floating as al 
dust in the atmosphere, settled on all bodies to develop oF y 
where the conditions of air, water and organic decomp posed 
favored; others denied the existence of germs, and SOP anic 
that under the dissolving action of the water, the-dead . 
substance took on life and so came out as new beings. F these 
Analogy afforded a strong argument for the first © 
opinions. The second has often been sustained by "undef cir 
researches claiming that animalcules were produced u 
cumstances in which all germs from external sources ed. 
cluded, and all present in the waters used had been destro. 
Frey and hebsea! 
succeeded i 
ous generation 
