On North American Spiders. 109 
Pickering of Philadelphia, to whom I am much indebted; but, when 
stuck through with a pin, and dried as other insects, these become so 
shriveled as to make it sometimes impossible to recognize them, and 
always so to describe new species. Spiders should be preserved in 
diluted alcohol, or brandy, in which they preserve their form, though 
their colors are usually impaired in it. 
The number of 125 species will appear very large, but I could 
have swelled the list to 150. Spiders differ from true insects, or at 
least winged insects, in their growing. ‘They come out from their 
eggs very minute, and continue to increase in size, probably for sev- 
eral years in many species; whereas, with few exceptions, insects 
come out of their pupa state, at once, with the size which is peculiar 
tothem. The Aranripgs, in their different ages, present differences 
of color and marking. The seasons also produce a change in the 
colors of some spiders; and, I am nearly convinced that the first frosts 
produce a total change in the dress of several described Errine 
which may be referred to one name. These are the considerations 
which have induced me to be very cautious in adopting new species, 
and comparing many specimens in different seasons, when possible, 
before I described them. 
a * s * * * * * * 
APPENDIX.—EDITOR. 
Juvenile Observations of President Edwards on Spiders. 
Ever since the following article on spiders, appeared in the late* 
edition of the works of President Edwards, with a memoir of his 
life, I have intended to republish the following extract, and it seems 
t0 follow naturally in the train of the learned monograph of Professor 
Hentz, Without pretending at present, to discuss the merits of the 
prin of Edwards, the observations recorded by him present a 
'Y Curious and interesting proof of philosophic attention, m a 
— years, and evince, that the rudiments of his great 
Pa a even at that immature age, more than beginning to be 
pe: é The first volume of his works, contains many other very 
‘ion and interesting speculations and observations on different sub- 
'S ol physical science ; on meteorology—on electricity—on crys- 
The ation—on geology—on chemistry—on an atomic theory, &c. 
¥ present indubitable evidence of that acuteness, vigor, precision 
Penetrating sagacity, which, had he devoted himself to physical 
Wee nk ee ee ee ee 
* 1829—S. Converse, New York, 10 Vols. 8vo. 
