DEATH AND ITS DISGUISES. 429 



spider was five years and three months in my possession. I liave not 

 sufficient data to estimate accurately the rapidity of growth in this spe- 

 cies, but judging from such facts and indications as I have ol>- 

 servecl tne anima l m ust h a ve been from eighteen months to two 

 years old when I received it from Dr. Lcidy. At the period of 

 its death, therefore, it must have been at least seven years old, and m,-iv 

 have been eight or more. It thus attained the distinction of having 

 reached the greatest age of any spider known to science. How long this 

 species and members of the Theraphosida) generally live in their natural 

 habitat is of course unknown. I have little doubt that they live much 

 longer than other tribes, but am inclined to think that it is not usual for 

 them to reach such an age as my tarantula " Leidy." In its case, as in 

 that of Sir John Lubbock's queen ant, human protection probably pro- 

 longed life. 



Other observations on the age of spiders fall in with this indication 

 of their vital endurance from the tarantula's prolonged age. Black wall 

 kept spiders of the species Tegenaria domestica and T. civilis to the age 

 of four years. 1 Moggridge made a calculation of the age of Trapdoor 

 spiders, based on average growth in nests of the young; for he established 

 the fact, which has subsequently been confirmed, that a young spider, in- 

 stead of abandoning its nest, enlarges it with its growth. He concluded 

 that it took at least four years to produce a full size trapdoor nest, and, of 

 course, the architect must be at least that old. 2 The most recent 

 Great information on this point is from Mr. Frederick Enock. s This 

 At us observer, in an extended and interesting communication on the 

 habits of the British Atypus, speaks of one individual which 

 he kept over three years, and which, judging from its size when first 

 captured, he puts at the age of six years. Other examples, under observa- 

 tion for more than two years, were well grown when first transferred to 

 his artificial colony, and at the date of his paper, June, 1885, were still 

 in good health. He ventures the inference that Atypus is about four years 

 in reaching maturity; then retains her young for eighteen months under 

 her care before turning them out to shift for themselves, and after that 

 lives in vigorous health for a period which he believes may sometimes 

 reach the advanced age of ten years. Thus, a spider's life may vary in 

 length, according to organization and surroundings, from a single season 

 to two, four, and even eight or ten years. 



I may add here, as in the same line of research, that Dr. George H. 

 Horn, a distinguished authority in the Coleoptera, has called my attention 

 to the fact that a female of Cybister roeselii was preserved for eight years 

 of continuous life by Dr. David Sharp. 



1 Spiders (ir. Bt. & Ir., page 8. 2 "Harvesting Ants and Trapdoor Spidrn-." psific lL'7. 

 8 "The Life History of Atypus piceus Sulz.," Trans. Entoni. Soc., London, Iss .'>. 

 page 41l>. 



