EARLY DAYS OF THE MICROSCOPE 



forth, and their horns, their bodies crammed all 

 over, their whole substance diaphanous, and through 

 that, the motion of their heart and blood. Also 

 little Handworms, which are indivisible, they are 

 so small, being with a needle prickt forth from their 

 trenches near the pool of water which they have 

 made in the skin, and being laid upon one's nail, 

 will discover by the sunlight their red heads and 

 feet they creep withal." The creatures called Hand- 

 worms are itch mites, which tunnel in the human 

 skin. 



In our chapter on Nature Study and the Micro- 

 scope we refer to the brown patches to be found on 

 the backs of fern fronds; it is interesting to note 

 that so long ago as 1646 Sir Thomas Browne had 

 quite a good idea of their structure. Describing 

 them, he said : " Whether these little dusty par- 

 ticles, upon the lower side of the leaves be seeds 

 we have not yet been able to determine by any 

 germination. But, by the help of magnifying 

 glasses we find these dusty atoms to be round at 

 first and fully representing seeds out of which at 

 last proceed little mites, almost invisible, so that 

 such as are old stand open, as being emptied of some 

 bodies firstly included, which though discernible in 

 Hartstongue, is more notoriously discoverable, in 

 some differences, of Brake or Fern." 



Two years earlier a noted scientist, Hodierna, 

 had made a special study of the eyes of insects and, 

 considering the crude instruments with which he 

 must have worked, his descriptions are wonderfully 



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