“ In the same spirit he investigated the generation of eels, which were at that time supposed, not only by the ignorant vulgar, but by “respectable and learned men,” to be produced from dew without the ordinary process of generation. ”

“ In 1680 he noticed that yeast consists of minute globular particles, and he described the different structure of the stem in monocotyledonous and dicotyledonous plants.
His researches in the life-history of various of the lower forms of animal life were in opposition to the doctrine that they could be “produced spontaneously, or bred from corruption.” Thus he showed that the weevils of granaries, in his time commonly supposed to be bred from wheat, as well as in it, are grubs hatched from eggs deposited by winged insects. ”

“ Though his researches were not conducted on any definite scientific plan, his powers of careful observation enabled him to make many interesting discoveries in the minute anatomy of man, the higher animals and insects. ”