25 per cerrt, \7hich is considerably more than f or "ftie old animals, 

 v;here the increment pmoimts to 15 per cent, in order to become 

 later yet less. The dui'ation of the second stage amounts to four 

 days. The third stage is considerably greater and more strongly 

 built than the preceding, its length is 13e5 nni» and, after five 

 days,, it changes into the fourth stage in which the larval life 

 is ended e 



The diu-ation of the various laical stages is, to a high degree, 

 dependent on the tenperatiure of the vmter; in rearing experiments 

 for which continuous nourishiaent is present in sufficient amounts, 

 it IE! almost the only factor which determines the length of this 

 period. In Table 5 is clerrlj'^ evident the relationship which exists 

 betiveen these both in rearing experiments o The nuiibers in this 

 Table are borrowed from Dutch rearing experiments, but however are 

 in agreoir.ent -vith those of other investigators. Peculiar are the 

 individual differences in groirtVi of the larvae xvhich \Tere exposed 

 in a container to exactly similar circumstances j \*en, for example, 

 the quickest growing individual had completed the larval stage 

 r>rter 12 days, the bulk came after 13, while also on the 14th day^ 

 t?ie last had yet not all moulted. 



Table 5. Duration of t he first development stages of 

 . the lobsters at various temperatures, in 

 days. 



Durrtion of the developmental stages Duration o? 



stages 



6 7(8) _5 18 



5(6) 6(7) 5 16 



5(4) 6 14(13) 



4(5) 5(6) 13(14) 



4(5) 5 13(12)(11) 



■ 4 5(4) 11(12)(10) 



4 4(5) 10(9) 



4(3) 4(5) 10(9) 



3 4(5) 9 



3(2) 4(5) 9 



2(3) 4(3) 9(8)(7) 



The young lobsters in the fourth stage, after the end of the 

 larval period, are usually 15-16 fiI.i. long and 13 da2/'s old; since 

 they are born in the middle of July, they have reached this stage 

 in August o Afber 15 days they enter the 5th stage and have then a 

 length of 17 rari, A striking difference exists in the color of the 

 groi.'ing lobsters, it is now— and indeed still in the follov/ing 

 stagcs~blue-green v:ith dead white flecks; ut v:hat time this colDr 

 changes into thrt of the adults i is not loioTm to me. The duration 



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