8 ENTOMOLOGICAL SOCIETY 



Moreover, there were several other protectively-colored 

 spiders available while the mud-wasps were abroad, and yet 

 not captured. For example, Leucauge hortorum, harmoniz- 

 ing with its surroundings in the same manner as Mangora 

 gibberosa, and much more common than that species, was not 

 in the mud-wasp cells examined by me. Misnmena vatia, 

 protected as is the Rundnia aleatoria, and fully as common, 

 was not found, but has been recorded by McCook, although 

 he may have confused it with an allied species. Drapctisca 

 socialis, Tmarus caudatus, Philodromus infiiscatus, Hyptiotes 

 cafi/atus, Epeira juniperi, Uioborus plumipes, Acacesia foliafa 

 — all protectively-colored spiders and apparently available as 

 food — were not taken by the wasps. 



If we look again at the lists, we see that the great bulk of 

 the mud-wasp captures are of spiders certainly not protected 

 by resemblance to their surroundings. Epeira trivittata, E. 

 parvida, the species of Argiope, and Xysticus triguttatiis, es- 

 pecially in their immature stages, are entirely defenseless. 

 These spiders are very fertile ; a great many eggs are in each 

 cocoon,* and it is by this means that they keep their position 

 in nature. My experience in collecting in these localities is 

 in line with this view. The adults of Epeira trivittata and 

 E. parvida and of Argiope are not much more common than 

 Cyclosa caudata or Rimcinia aleatoria, but the young of the 

 former spiders are very much more numerous than the young 

 of the protectively-colored species. 



Resemblance to escape enemies is apparently a last resort 

 of a spider incapable of maintaining its position in nature by 

 its fertility or its facility in the capture of prey. Cyclosa, for 

 example, has less than lOO eggs, often but 50, in a cocoon, 

 while the ant-like spiders have still fewer, one of them but 3 

 eggs in a cocoon. 



This protectively-colored group of spiders could hardly 

 exist were it not for the presence of the extremely fertile 

 group, from which the mud-daubers and other enemies of 

 spiders secure the bulk of their food. Like the farmer who 

 plants ten kernels of corn in each hill, " two for the blackbird, 



' Argiope, for example, has 1,000 to 2,000 eggs in a cocoon. 



