62 PECKHAM. [Vol. 1. 



meaning of a protective peculiarity can be determined only 

 when the animal is seen in its natural home. The number of 

 strangely modified forms depicted in descriptive works on 

 spiders is enormous. Bodies are twisted, elongated, inflated, 

 flattened, truncated, covered with tubercles or spines, enclosed 

 within chitinous plates, colored like bark, like lichens, like 

 flowers of every imaginable hue, like bird droppings, like sand 

 or stones, and in everyone of these modifications there is doubt- 

 less an adaptation of the spider to its surroundings which, 

 when it is studied out of its natural relations, we can only 

 guess at. 



It has been well said that in these protective resemblances 

 those features of the portrait are most attended to by nature 

 which produce the most effective deception when seen in 

 nature; the faithfulness of the resemblance being much less 

 striking when seen in the cabinet.* 



Before entering upon a consideration of protective modifi- 

 cations, I wish to give some account of the enemies of spiders 

 and also to call attention to the remarkable variations in the 

 fertility of the different species. 



ENEMIES OF SPIDERS. 



The enemies of spiders are numerous and vary greatly in 

 different countries. Among them we may enumerate birds, 

 wasps, lizards, snakes, monkeys, ichneumons, some kinds of 

 ants, and spiders. They are also eaten in inconsiderable num- 

 bers by beetles and by fishes. 



Outside of the Trochilidaj comparatively few of the North 

 American birds feed to any extent upon spiders, although thej' 

 form an insignificant part of the food supply of many species.f 



*H. W. Bates, in Lepldoptera of the Amazon Valley, p. 507. 



fProf. F. H. King has examined the stomachs of 1608 Wisconsin birds, including 

 five humming-birds, 34 families being represented. In these he found, among other 

 things, 1779 Hymenoptera, 1262 Ooleoptera and 52 spiders. The whole number of birds 

 eating HymenopUra was 189, the whole number eating Coleoptera 430 and the whole 

 number eating spiders 35. 



Prof. S. A. Forbes linds that spiders appear to the following extent in the food 

 of Illinois birds: Eobin, I'i,;; (Jatbird, 2% ; Brown Thrush, 1°„; other Thrushes, 1%; 



