LEEUWENHOEK 211 



bore hair-like spinnerets, each of which emitted its own 

 filament. 



In October spiders were enclosed separately in glass 

 tubes to see whether they would lay eggs. Some of 

 them spun webs, within which they laid rounded masses, 

 half an inch in diameter, composed of yellow eggs. 

 Leeuwenhoek found to his surprise that the eggs are not 

 passed out from the extremity of the abdomen, but 

 from the under surface of its fore end. In a warm room 

 little spiders hatched out during the winter, before any 

 food was ready for them ; some devoured the bodies 

 of their companions or the unfertilised eggs. Letter 

 143 tells how an unnamed friend had seen what were 

 no doubt the palps of the male spider used to fertilise 

 the female ; anatomical and other considerations made it 

 impossible for Leeuwenhoek to accept this true story. 



An Inquiry into the Generation of the Edible Mussel 



(Mytilus) 1 



It was with the intention of refuting the doctrine that 

 shell-fishes are generated from the mud of the sea- 

 bottom that Leeuwenhoek took up this inquiry ; he 

 would, as he says, have found it just as easy to believe 

 that a whale could be generated from mud. He quotes 

 testimony to prove that mussel-spawn or milt at certain 

 seasons makes the sea white, and thinks it certain that 

 the spawn settles at the bottom, to replenish the ex- 

 hausted mussel-beds. But until the spawn was clearly 

 traced to the mussel the evidence did not carry convic- 

 tion. Leeuwenhoek dissected mussels, and searched in 

 vain for their eggs, though he found other things to 

 interest him, such as the play of cilia on the gill, which 



'■Epist. 83, Arc. Nat. (1694). Vol. II, pp. 417-439. 



