Mr. Black wall on Geometric Spiders. 181 



Art. XXVIII. On the manner in which the Geometric Spi- 

 ders construct their Nets. By John Blackwall, Esq.^ 

 F.L.S , Sec. 



Few animals of solitary habits are endowed with more extraordinary 

 instincts than Spiders. The ardent affection for their offspring so strik- 

 ingly manifested by some species ; the exquisite skill displayed by many 

 in fabricating silken cocoons to contain their eggs, and in the construc- 

 tion of their habitations ; the highly curious contrivances by means of 

 which others traverse the regions of air, or descend beneath the surface 

 of water ; and the various stratagems had recourse to by all in eluding 

 their numerous enemies and in securing their living prey, are eminently 

 calculated to attract the attention and elicit the admiration of every per- 

 son who has a mind alive to the wonderful physiological phenomena 

 exhibited by the inferior orders of animated beings. But interesting as 

 the general economy of this remarkable tribe of animals is, and well 

 deserving of more minute investigation than has hitherto been bestowed 

 upon it, on the present occasion I purpose to limit my observations to 

 the manner in which several British species of geometric Spiders con- 

 struct their snares. 



By the elegance of their symmetrical structure and their extreme deli- 

 cacy of texture, the nets of these uneducated geometricians never fail to 

 excite astonishment, even in the most thoughtless observer, and the pen 

 of the natural historian has been frequently employed in describing the 

 singular process by which they are formed. Among the various authors 

 whose works I have consulted, Messrs. Kirby and and Spence have given 

 the most circumstantial account of this process in their comprehensive 

 and excellent Introduction to Entomology;* I shall, therefore, avail my- 

 self of what these gentlemen have done, without reserve, introducing 

 such particulars in addition as have resulted from my own researches, 

 and attempting to solve a few of those difficulties which they have left 

 without explanation. 



The geometric Spiders usually suspend their nets in an oblique or 

 nearly vertical position, fixing them to trees, shrubs, plants, buildings. &c. 



* Vol. I.. Letter XIII. 



