io8 Journal of Comparative Neurology. 



jar. In a few days this web had been increased until the main 

 sheet formed a horizontal partition in the jar. This sheet was 

 attached to the tops of all of the posts. I destroyed this web. 



B. — A small rectangular tube was placed on the ground 

 between two posts. The web was reconstructed" This time 

 the gallery was located on the ground near one of the uprights. 

 The gallery was held extended by tension strings which extended 

 from the sides of the gallery to the tube and to the side of the 

 jar. There were two main sheets, one extending form each ex- 

 tremity of the gallery, outward and downward to the floor. 

 During the second night a vertical guard sheet was erected, 

 which extended from the gallery to the post diagonally opposite. 

 A few days after this web had been completed the spider was 

 disturbed while resting in the gallery. It immediately left it. 

 The web was not injured in the least. 



C. — The night following its hasty retreat from the gallery, 

 the spider constructed another web. The main sheet was hori- 

 zontal and on a level with the top of the posts. It was pentago- 

 nal, being attached to the jar, to three posts and to the upper 

 edge of the guard sheet of the lower web. Where they met 

 the main sheet of the lower they were completely fused. The 

 gallery was an L shape tube It consisted of a horizontal 

 portion extending along the sand, and of a sub-vertical portion 

 ascending along the jar. 



The two webs thus unequaly combined formed a two story 

 house ; and the L shaped gallery formed a stairway leading from 

 the first to the second story. Indeed the spider used sometimes 

 one story and sometimes the other. At one time it would await 

 its prey in the upper gallery ; while at another time it would 

 await its prey in the lower gallery. 



SUMMARY. 



Various writers from Fr. DahU to McCook- have informed 

 us that the orb- weaving spiders vary the structure of their webs 

 to suit the environment, and that they patch their webs, when 



1. Op. cit II. 



2. American Spiders and Their Spinning Work. 



