STRUCTURE AND ECONOMY OF SPIDERS. 305 
gently along the underside of the tarsi, from their 
extremities towards the tibie, they will be found, 
even in dried specimens, to adhere powerfully to 
the cuticle, the sensation occasioned by this pro- 
ceeding exciting in the mind the idea that they are 
smeared with some viscous matter. At Plate I. 
an appendage from one of the tarsal brushes of 
Mygale avicularia is represented by fig. 5, and one 
of the compound hairs which clothe the limbs of 
Tegenaria civilis by fig. 6. It is almost unnecessary 
to offer any caution against confounding objects so 
essentially distinct. 
Dr. Leach, in treating upon spiders in the article 
“ Annulosa,” published in the Supplement to the 
‘Encyclopedia Britannica,’ p. 435, remarks that 
“when about to cast their covering, they suspend 
themselves in some corner, and creep out of a crack 
which takes place on their back, gradually withdraw- 
ing their legs from the skin, as if from a glove.” 
With deference to so accomplished a zoologist, I 
may be allowed to observe that this statement is not 
in strict accordance with my own experience; and 
as I do not remember to have met with a satisfactory 
account of the moulting of spiders, in the course of 
my reading, I shall endeavour to elucidate this 
curious subject by giving such particulars relative 
to it as have fallen under my notice. 
Considering the apparent uniformity of the process 
by which this important change in the external con- 
X 
