PECKHAM. 



[Vol. 2, 



We afterward found that a female picata commonly made 

 three cocoons in a season, some of them containing three and 

 some four eggs. Synemosyna formica has probably about the 

 same rate of reproduction, since we once found a cocoon of that 



Figs. 1 and 2.— Syuageles picala. Positions of male approaching female. 



species containing four eggs. AVe have elsewhere called atten- 

 tion to the low fertility of the ant-like sjsiders (some species of 

 Attidfe lay 180 eggs), and, have suggested that if there is an 

 inverse variation in every species between its birth-rate and its 

 powers of maintenance, we must accept the conclusion that 



Fig. 3. — Synageles picala. Side view of male approaching female. 



these small, weak and defenseless spiders derive an immense 

 advantage from their imitation of ants, their mimetic form 

 enabling them to escape from their enemies. 



About one hundred species of ant-like Attidse have been 

 described. Their distribution is somewhat peculiar. They are 

 found in almost all parts of the world, and seem as well able to 

 live in one climate as in another, but it is in two widely sepa- 



