DEVELOPMENT AND IMMATURE STAGES. 137 



kindness of Mr. Waddington; I used the ergot as 

 the sole food during the experiments, always carefully 

 sterilising it. 



It was early in November, 1900, when it first struck 

 me that it was desirable to check the number of 

 ecdyses myself, and to endeavour to obtain some in- 

 formation as to the length of time occupied by the 

 various stages. I was aware that the season of the 

 year was most unfavourable for the investigation ; still, 

 as I had the time before me, I thought that it would be 

 best to endeavour to see if I could learn anything in 

 winter. This involved a much greater expenditure of 

 time and trouble than I had anticipated ; but it resulted 

 in discovering one point in the life-histories which was 

 entirely unsuspected by me; and which, as far as I 

 know, has not been recorded by any arachnologist. I 

 found that a creature would become inert exactly as if 

 it were about to pass through an ecdysis ; it was per- 

 fectly motionless, and had the legs either stretched out 

 or curled up, and would lie in any position it happened 

 to fall in. In this condition it would remain for days 

 or even months ; then suddenly one day I would find it 

 quite active ; the natural supposition was that it had 

 emerged, but I did not see any cast skin. I thought 

 it might have eaten it ; but in the cases where I saw 

 the creature emerge it never did eat the cast skin; 

 moreover in those cases where there was not any cast 

 skin the creature never looked as if it were newly 

 emerged. From long habit of noticing them the 

 observer gets to know the appearance of a freshly 

 emerged specimen ; the abdomen is flatter than in one 

 that has emerged some time, and is much more 

 dimpled ; the specimens which have been out some 

 time look fully-fed and arched on the back, and are 

 without dimples ; moreover the freshly emerged speci- 

 mens are more transparent and lighter in colour. I 

 was greatly puzzled by this at first, and feared that I 

 had somehow missed the ecdysis; but by long and 

 constant watching in numerous cases I found that 



