The Structttre and Habits of Spiders. 89 



curious humps and horns on their heads, 

 Fig. 44. The most extreme example is Fig. 

 45, where the eyes are carried up on the end of 

 the horn. The females of all 

 these species have plain round 

 heads ; and what use the humps 

 are to the males nobody knows. 

 The peculiar organs by which 



Fig. 45. 



the adult males and females can 

 always be distinguished are, in the males, the 

 palpal organs, on the ends of the palpi ; and, 

 in the females, the epigynum, Fig. i. 



PALPAL ORGANS. 



As the male spider gets nearly^ full grown, 

 the terminal joints of the palpi become swollen, 



Fig. 46. 



and, after the last moult, the palpal organs are 

 uncovered, 



