218 



AN INTRODUCTION TO ZOOLOGY 



TABLE IX 



THE DURATION OF THE LARVAL STAGES, AND THE SIZE AND HABITS OF YOUNG 

 CRAYFISHES DURING THE FIRST SUMMER 



pendent of the mother, although they at first always return to her 

 when separated. From this time on the larvae shift for themselves, 



TABLE X 



THE AVERAGE RATE OF GROWTH OF A CRAYFISH (CdmbarUS affinis) 



growing rapidly, and molting at least four more times during 

 the first summer. The first winter no growth nor molts occur. 

 There are four or five molts the second summer, three or four in 

 the third summer, and perhaps one or two in the fourth summer. 



