Experiments Y/ere riade v/ith: 



A) Finely cruuhed crabs (uvery 3fl hour) 



B) Minced shrimp 



C) No food, only algae, grown v/ith different bryozocns, 

 hydroidsj etc-> were put into the boxes 



B and C vrere started at the same time; A tvro days earlier (see 

 the tables) o 



A) i^ave about 17 per cent in the 4th stage 



■d\ II H TO '' 'I " " 'I " 



C) " " " " (they all died a^er tvro days) 



The experiments firom iiu,-;ust 10 to Aui!;ust 21 i^i-'ve the folloviring 

 results v/hen vre tcke into consideration the tijac between each feeding 

 (with :iinced crabs )- 



D) fed every 12th hour^ gives 12 per cent 



E) " " 6th " " 12 " " 



F) " " 3d " " 43 " " 



However, \-rhen the experiment wns completed, the young had not 

 c.ll reached the 4th stage* 



From time to time experiments were also made with finely ground 

 fish, but as this polluted the water, vre stopped the experiments* 

 Besides, v/hct T.dll be seen from the above mentioned experiment., ic,e» 

 th't a frequent feediiiB, v/ith crabs seens to give the best results, I 

 have also made the discovery that the crab (both entrails, the 

 "support for the feet" and the claws) ought to be crushed very finely 

 and be screened for the young in the boxes » One thereby obtains a 

 fine distribution of the food; also, that v/hich is. not used will grad- 

 ually be carried away by t?\e strea^Ti of water out of t he boxes, so that 

 it will not pollute the water fir the young; but it necessitates a 

 plentifu.l and frequent feeding; v/hen we had the largest number of boxes 

 working (i«e», 8)(, v:e used three crabs rt a tine every 3d houTo 

 BXirther, I think it is important to feed the young already in the 

 hatching boxes; howuver, I have made no experi^aents in this respecto 



Vifith regard to the current in the rearing boxes, ^rhich is also 

 of gref.t importance for good results, I have also made different ex- 

 periments - which cannot be given in table form* 



In the rearing boxes the ^vater gets a rotating mcTvenent, and in 

 spite of the rise of the propeller v.-ings, the suction from the bottom- 

 windovv's is very small; the even rotation-will further cause o dead- 

 point in the water near t he propeller axis, whore both the dead and 

 the living young will gather - and often bo lum.ped together at the 

 bottom. 



To prevent these difficulties I have experiment a llj' placed in- 

 clined deals (about 40 x 75 centimeters) in the box, and placed tliem 



