6 THOS. H. MONTGOMERY, JR. 



may cease to spin, seemingly being cognizant of something out 

 of the ordinary course. Or the cover may be incompletely made, 

 leaving the egg mass partially exposed, this is apparently due to 

 lack of sufficient space for the spinning operations. Once a 

 mistake is made the spider appears to be unable to rectify it, a 

 fact that I have remarked in my earlier observations (/. r.) ; 

 the whole process appears to be strictly instinctive and the 

 spider seems unable to modify it more than quantitatively, and 

 unable to learn by experience. An individual may make an im- 

 perfect cocoon, then construct a following one quite perfect ; or the 

 reverse may happen. When the cocoon is particularly irregular, 

 as when the egg mass becomes more or less broken, the spider 

 may either eat the eggs, or may detach them from the web 

 and allow them to fall to the ground. 



6. Time Intervals between Successive Cocoons Formed by the 

 same Individual. --Of 113 timed intervals between successive 

 cocoons raised in my cages, there was one interval of 2 days, 2 

 of 3 days, 13 of 4 days, 26 of 5 days, 18 of 6 days, 19 of 7 days, 

 12 of 8 days, 10 of 9 days, 3 of 10 days, 4 of 1 1 days, 4 of I 2 

 days, and I of 1 3 days. More than half of the intervals ranged 

 from 5 to 7 days. In all probability the rapidity in the rate of 

 the succession of cocoons depends upon the degree of nourish- 

 ment of the spider, because some that I purposely starved 

 furnished no cocoons at all. My captives were of course not as 

 well fed as they would have been in the wild state, and though 

 I kept them fairly well supplied with young grasshoppers and 

 locustids this by no means equalled their natural diet in either 

 variety or amount. It is probable that these spiders in a natural 

 state, with normal feeding, would furnish on the average cocoons 

 at intervals of from four to six days. The shortest time in 

 which a succession of 4 cocoons was made by any one of my 

 spiders was 14 days, comprising one interval of 4 days and two 

 of 5 days. The largest number of cocoons I have found in any 

 wild web was eight. 



7. HatcJiing of the Young. Thirty-nine cocoons were kept 

 to determine the time of hatching of the young. Of these, 3 

 failed to hatch; 3 hatched after an interval of 1 1 days ; 3, of 13 

 days ; 1 8, of 14 days ; 2, of 15 days ; 9, of 16 days ; and I, of 



