Mr. Blackwall on Geometric Spiders. 181 
Arr. XXVIII. On the manner in which the Geometric Spi- 
ders construct their Nets. By Joun Bracxwatt, Esq., 
FLLS., &c. 
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 seyeral 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 haye 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. L, Letter XII. 
