no Journal of Comparative Neurology. 



At one time a spider may construct a web which contains 

 but one main sheet [Ex. XXXVI, A]; later the same spider, 

 under the same conditions, may construct a web with two main 

 sheets connected by a common gallery [Ex. XXX VLB]; still 

 later the spider may remodel this web and transform it into a 

 compound web having an upper and lower story connected by 

 a special gallery [Ex. XXXVI,C]. 



The gallery spiders patch their webs, when accident renders 

 it necessary [Ex. XXXI-XXXIV]. They also remodel their 

 webs [Ex. XXXV, D, XXXVI, C]. 



The fact that all of these webs consist of a more or less ex 

 panded sheet to which a gallery is attached seems to indicate 

 that there is an inherited tendency in gallery spiders to contruct 

 galleries. 



On the other hand, if instinct dictated the details of construc- 

 tion, then all webs constructed by individuals of the same species 

 should be identical. But this is not the case. Even where the 

 external environment is the same, webs of different individuals 

 of the same species are often dissimilar. Furthermore, on the 

 grounds that instinct is the only determining factor, how can we 

 account for the fact that under the same external conditions, the 

 same individual constructs dissimilar webs. 



All things considered, I think we may safely conclude, that 

 an mstinctive impulse prompts gallery spiders to weave gallery 

 webs, but the details of construction are the products of intelli- 

 gent action. 



