250 



AMERICAN SPIDERS AND THEIR SPINNINGWORK. 



series had the increase been less than one line in width, which was equal 

 to an increase of one-fourth the original width of the door. 



We can scarcely venture from such limited premises to draw any precise 

 conclusions. But if we suppose that during the entire course the nests 

 increased on an average by about four lines in diameter, and assume that 

 the rate of growth continues the same, the nest of the infant spider, whose 

 surface door measures scarcely a line across, would still require four years 

 to attain the dimensions of some of the largest double doors, whose surface 

 doors measure ten lines across. 1 



In the nests of several females of Cteniza ariana Walck., on the island 



of Niros, in the Grecian Archipelago, Mr. Erber found eggs at the bottom 



of the tube attached by separate threads, and not placed in 



Grecian cocoons. The young spiders when hatched were turned out from 



a . the asylum of their mother's nest, and these creatures were 



Trfl 1 1 ft T1 



Species, found, scarcely two lines long, already established in nests three 

 inches deep and furnished with perfect trapdoors, specimens of 

 which were collected. 2 



Costa states that the young of Nemesia rneredioualis, observed by him in 

 the neighborhood of Naples, remain in the bottom of the maternal tube. 



The mother herself stands 

 at the door, holding the 

 lid raised by means of the 

 four anterior feet and the 

 palpi, the curved extremi- 

 ties of which she inserts 

 between the rim of the 

 tube and the door. Some- 

 times the limbs do not ap- 

 pear, but the spider leaves 

 only a chink for observa- 

 tion. He also observed 

 the fact that the young spiders make perfect little tubes entirely inde- 

 pendent of the maternal nest. 3 



FIG. 265. The trapdoor and burrow of a young Nemesia 

 meredionalis. Natural size. (After Moggridge.) 



XV. 



Most persons who consider the above facts will cordially join with Mr. 



Moggridge in thinking that these very small trapdoor nests, built as they 

 are by minute spiders probably not very long hatched from the 



Marvels eggs, must rank among the most marvelous structures of the 

 kind with which we are acquainted. That so young and weak a 

 creature should be able to excavate a tube in the earth many 



of In- 

 stinct. 



1 Mo..rrid<:e, Trapdoor Spiders, pa>re 127. 



2 Verhand. der k. k. Zoologish-botanisclior Vereiii in Wien, Vol. XVI 1 1. (IStiS), page 905. 



3 Costa, Fauna del Regno di Napoli, Anwnidi 11801), page 14, tab. i., Figs. 1-4. 



