The Life of the Caterpillar 



on the 19th, the night of the lowest press- 

 ure, 29 in., not a caterpillar ventures out- 

 side. 



As the wind and rain can have no effect 

 on my colonies under glass, one is led to sup- 

 pose that atmospheric pressure, with its 

 physiological results, so difficult to define, is 

 here the principal factor. As for the tem- 

 perature, within moderate limits there is no 

 need to discuss it. The Processionaries have 

 a robust constitution, as behoves spinners who 

 work in the open air in midwinter. However 

 piercing the cold, so long as it does not freeze, 

 when the hour comes for working or feeding 

 they spin on the surface of the nest or browse 

 on the neighbouring branches. 



Another example. According to the me- 

 teorological chart in the Temps, a depression 

 whose centre is near the lies Sanguinaires, at 

 the entrance of the Gulf of Ajaccio, reaches 

 my neighbourhood, with a minimum of 29.2 

 in., on the 9th of January. A tempestuous 

 wind gets up. For the first time this year 

 there is a respectable frost. The ice on the 

 large pond in the garden is two or three inches 

 thick. This wild weather lasts for five days. 

 Of course, the garden caterpillars do not 



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