HI THE QUARTERLY REVIEW OF BIOLOGY 



for reaching maturity will probably vary the following year; two molts in each of 



by as much as two years. the next seven years; and one in each of 



If the observations made on the several the last three years, making a total of 



Fig. z. Male Tarantula over Sperm Wed 



(Photograph by W. J. Baerg) 



spiders may further be applied to RTj, the 

 mature male, he has gone through the 

 following molts: the first molt about 

 three or four weeks after hatching, when 

 emerging from the cocoon; four molts in 



molts for the entire life 



twenty-two 

 cycle. 



During the four years that RT X has been 

 under observation, he was taken for a 

 female. The legs apparently resembled, 



