As ■unoertcin cs the calculations on the grovrth of the lobsters 

 are also on our coasts one cannot hardly expect that one ought to 

 be able to drav; from this definite arguments for an estimation of 

 the grovvth of the lobster in the southern Horth Sea» Although I 

 ho'.TCver believe that Ehreribaum in. his calculations has reckoned too 

 large numbers so I essentially conclude this fJcom a comparison 

 between Elirenbaiim's tables (1, po 285) on the groirth of the Helgo- 

 land lobster and ny observations on the grovrth of the lobster of 

 the Norv'/egian West Coast# This comparison shows indeed the same 

 variations on both coasts, but in regard to the older individuals no 

 ■ gror.ter average gro'V'.'th is evident for the southerly North Sea. Also 

 no proof is present that the lobster at Helgoland just ns little as 

 on the Norvregian West Coast should noult twice a year at a size of 

 21 eras, and m.ore, which was the case vfith Brook's spocimense On 

 the contrary Ehrenbaum's example— namely. that moulting takes place 

 principally from the beginning of July to the beginning of August 

 (l, p« 289)- — indicates thereof that two moultings in the same year 

 canjnot readily occia-e Under these circ\:uTistances hov/ever at least 

 one year must be added to the o.ge given by Ehrenbaum for sexual 

 matiArity and the latter can commence at the earliest d-uring the 

 8th grovfth period (in the 8th year of life);* Moreover indeed these 

 same groups v/ith regard to growth v/o\ild seen to be found in the 

 southern North Sea as on the Norvregian Coast and a definite ratio 

 between size and age might also not be able to be provene 



On the East Coast of Scotland (Aberdeen) V-filliamson has made 

 investigations on lobster rearing and he declares briefly that the 

 larvae here require one month to six weeks to reach the 5th stage 

 (the stage beyond the Megalops) if the development occiats during 

 the warmer seasons The latter tine night very nearly correspond, 

 as mentioned above, with that one that is required on the average 

 for the proper development on the Norv/egian YIest Coastc In regard 

 to grown-up individuals, we have statement fro}.i Williamson (p» 92) 

 ViTho has investigated the grovjth of 13 such ones from approximr.tely 

 24 to 33 cms* To judge from these indi^'-iduals the grovrth is gen- 

 erally less than f or t he lobster on our West Coast: for two individ- 

 uals it was not noticeable, for seven 0«63 cmso, for one Oo8 cnsoj 

 for one approximately 1 cm«, for one 1»3 and for one 1«6 cms. 



The experiments in lobster rearing that v;ere made by Chadv/ick 

 at the Liverpool Biological Station (Port Erin) shoviT in regard to 

 the larval stages about the same duration as on the Norv/egian West 

 Coast, since the first three larval stages are passed tlirough in 

 between three and four v/eeks. 



In the Channel, in t he vicinity of Falmouth, Cunningham has 

 mride rearing experiments. These took place fron the end of May to 

 the end of June and he specifies the duration of tlie first tliree 

 stages as approximately 23 to 25 days; this rather corresponds 

 therefore T;ith the conditions on our coasts* Cuixsiingham does not 

 specify the water temperature but according to temperature data 

 given in the sane v/ork (p. 39) from places in the vicinity the 



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