In the year of 1657 I discovered very small living creatures in rain water.

A man has always to be busy with his thoughts if anything is to be accomplished.

I've spent more time than many will believe [making microscopic observations], but I've done them with joy, and I've taken no notice those who have said why take so much trouble and what good is it?

Whenever I found out anything remarkable, I have thought it my duty to put down my discovery on paper, so that all ingenious people might be informed thereof.

Please bear in mind that my observations and thoughts are the outcome of my own unaided impulse and curiosity alone; for, besides myself, in our town there be no philosophers who practice this art, so pray, take not amiss my poor pen and the liberty I here take in setting down my random notions.

We will admit that, out of the mud or sand which is found on the seashore or the beds of our rivers, at low water, shellfish or testaceous animals come forth, but it does not from thence by any means follow that they are produced without any regular course of generation.