460 ]Mr. F. Pollock on the History and 



From the extreme tenuity and want of strength of these webs, 

 there are very few insects feeble enough to be held by them ; and 

 the consequence is, that hundreds of the spiders, at this precari- 

 ous period of their existence, perish from starvation or other 

 causes, and I have been led to the conclusion that not more than 

 one or two (if so many) out of each cocoon survive, though, 

 having once passed this period, very few of them appear to die 

 until the natural time arrives. 



It is next to impossible to watch them closely, or speak with 

 any degree of certainty about them, at this early stage of their 

 life, not only on account of their being so small, but because 

 they are then exceedingly migratory. If there be a gentle 

 breeze and they feel so disposed, they float away on the light 

 gossamer threads they can let out to almost any distance they 

 please, without one^s being able to prevent it. 



In the hope that I could the better observe them, I had a large 

 glass case made to keep them in ; but I found that they did not 

 thrive well in captivity, especially at this period of their life ; 

 for, amongst thousands confined for four or five months, not one 

 appeared to grow larger, or change in any respect, except perhaps 

 to become a little darker. 



In the glass case the young ones never made webs, but merely 

 lines; and, without a regularly constructed web, spiders scarcely 

 have the power, or apparently the inclination, to catch prey : so 

 they gradually died off. 



" It is all fish, however, that comes to the spider's net.'' They 

 make no distinction between a brother and a blue-bottle fly ; and 

 though the young did not live upon each other in confinement, 

 they were food (and the only convenient food I could get) for 

 some others of a size larger in the glass case, which did make 

 webs. 



A fortnight after the young spider leaves the cocoon, it begins 

 to construct snares, to feed, to grow, and to become darker. 



I cannot say positively, but I believe, in a month or two from 

 that time, according to the food it gets, it changes its skin. 



The females have nine changes after leaving the cocoon. From 

 the first to the eighth these changes take place pretty regularly, 

 under favourable circumstances, — in times increasing gradually 

 from about fifteen to twenty-five days, though one spider in the 

 glass case (having had one or two changes) remained for forty- 

 five days without changing, and then died. 



For about two days preceding each change the spider seems 

 to eat nothing, and to remain motionless. 



The operation of getting out of the old skin is a strange-look- 

 ing performance, and is thus effected : — The spider is fastened 

 firmly, by a thread from the spinnerets, close to the underside 



