444 Dr. J. Hjort. Observations on the Distribution of 



three curves (figs. 1 and 2*) all show a marked increase in the weight of the 

 rats when given the seaweed. Tig. 1, the lower curve, represents the growth 

 on fresh seaweed, kept in cold store. The increase is not so marked as the 

 two other curves showing the effect of dried seaweed. This produced an 

 enormous increase in the weight. The dried seaweed was added to the food 

 as a fine green powder and was thoroughly mixed with the food. 



5 10 15 20 25 30 35 5 10 15 20 25 30 35 40 45 



Fig. 1. — Lower curve, fresh ulva, ad lib. Fig. 2. — Dried ulva, 1 grin, per day. 



Upper curve, dried ulva, 1 grm. 

 per day. 



In order to see if the growth-promoting factors of the ulva were soluble in 

 its fats, dried powder of ulva was extracted with acetone and the oil given 

 (1 or 2 drops a day) to the rats. The resulting growth-curves may be seen 



100i 1 1 1 , 1 1 1 , , 



Fig. 3. — Extract (by acetone) of ulva, Fig. 4. — Point 1, added 1 gr. sterilised 



two drops a day. diatoms per day. Point 2, 1'5 grm. 



dried diatoms per day. Point 3, 2 drops 

 benzene extract of diatoms per day. 



* In all the figures the abscissa gives the number of days of experiment, the ordinate 

 the weight in grams. 



