LIFE HISTORY OF DES.Mf )( .\A I 1 1U -> 11 SCA. 



273 



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8 9 to ii 12 13 14 15 



--> x 

 '/. C 



GRAPH I., showing the growth in length during the terrestrial larval period 

 (cf. first column of statistics, Table I.). Lines A, BC, DE, and F correspond to 

 the similarly designated stages, the average age of each stage in days being indi- 

 cated by the number at the bottom of the line and the average length ( X 2) by the 

 length of the line. Line G shows, for comparison with F, the average length of 42 

 aquatic larvae collected during the months ot September and October. 



days in advance of others; and the differences in the distances 

 of nests from the water would introduce still another variable 

 factor. 



While the limits of the terrestrial larval stage are somewhat 

 indefinite, the structural changes which take place during this 

 period are very important, and for the study of these changes the 

 above described material may be tabulated as follows (see 

 Plates I. and II.): 



Stage A. Two specimens killed September 25. Just hatched. Average length 

 15.25 mm. 



Stage B. Three specimens killed October i. Average age 3 days. As these 

 were taken from near the nest the actual age of all of them is probably less. 

 Average length 16.83 mm. 



Stage C. Two specimens killed October i. Age as in the case of stage B, 

 but as these two were taken from the pool of water at a greater distance from the 

 nest, their actual age is probably above the average of 3 days. Average length 18 

 mm. Average length of B and C together is 17.415 mm. 



Stage D. Five specimens killed October 5. Average age 7j/ days. Average 

 length of the two uninjured ones 17.652 mm. 



Stage E. One specimen killed October 6. Average age 8 }/ days. Length 

 18.25 mm. Average length of D and E together is 17.83 mm. 



Stage F. Three specimens killed October 14. Average age 15 days. Average 

 length 20.17 mm. 



