The Spiders' Exodus 



Next to the tuft, the wing is the most satis- 

 factory contrivance for dissemination by wind. 

 Thanks to their membranous edge, which gives 

 them the appearance of thin scales, the seeds 

 of the yellow wall-flower reach high cornices 

 of buildings, clefts of inaccessible rocks, cran- 

 nies in old walls, and sprout in the remnant of 

 mould bequeathed by the mosses that were 

 there before them. 



The samaras, or keys, of the elm, formed 

 of a broad, light fan with the seed cased in its 

 centre; those of the maple, joined in pairs and 

 resembling the unfurled wings of a bird; those 

 of the ash, carved like the blade of an oar, 

 perform the most distant journeys when 

 driven before the storm. 



Like the plant, the insect also sometimes 

 possesses travelling-apparatus, means of dis- 

 semination that allow large families to 

 disperse quickly over the country, so 

 that each member may have his place in 

 the sun without injuring his neighbour; and 

 these apparatus, these methods vie in 

 ingenuity with the elm's samara, the dande- 

 lion-plume and the catapult of the squirting 

 cucumber. 



Let us consider, in particular, the Epeira?, 



189 



