no THE QUARTERLY REVIEW OF BIOLOGY 



on observations made on a number of have been under observation throughout 

 spiders in various stages of development, their life time from hatching till death 



Fig. i. Above: Mature Male Tarantula. Below: Female Tarantula 14 to 16 Years Old 

 (Photograph by David G. Hall) 



ranging from newly hatched individuals after maturity; but the observations that 

 to fully matured adults. No individuals have been made for a number of years on 



