DAPHNIA PULEX MULLER 



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f*- ro 



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cr P 

 Cu-. 



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ro - 



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C E- 

 p" 



a. 



ro 



o 



heavy chitinous cuticle on the outer surface. Once produced, the 

 chitinous cuticle is incapable of further growth. It hardens and 

 becomes the skeleton. Increase in the size of the animal can be 

 therefore accomplished only by a process of moulting during 

 which the old skeleton is thrown off. The newly produced 



