63 



Cherry Creek :uid [lut in :i i^lass jar partially tilled with lake water. On 

 July 11, sixty of these were selected for operation. The right hind leg was 

 removed fx'om each of thirty and the two pairs of iiind legs were removed 

 from the other thirty. Each series was put into a glass dish partially 

 tilled with lalve water. 'J'he water was changed dail.v. At the end of 

 eigliteen days tlie death rate had heeu so great tliat only six individuals 

 of each series survived. On examination it was found that some regenera- 

 tion had talien place and it was thouglit best to Ivill those that survived. 

 They were liilled in eighty-five per cent, alcohol. The right hind leg of 

 each individual was removed and measured under the microscope segment 

 by segment. Likewise the right second leg was removed and measured. 

 A comparison was made between the regenerated right hind leg and the 

 normal right second leg. Also the body length was measured and its 

 length was compared with the length of the regenerated right hind leg. 



On July 8, 1907, the author took several gammarus from the lake near 

 the mouth of Cherry Creek. On July 8, 9, and 10 the right hind leg was 

 removed from each of twenty-six individuals and the two pairs of hind 

 legs were removed from tliirty individuals. This time the legs were 

 mounted in glycerine. Each ganunarus was placed in a separate dish. 

 Tlie animals wei'e fed every five days and the water was changed daily. 

 Two days after the moult the gammarus were killed in eighty-five per cent, 

 alcohol. The right hind leg was removed and measured as before. The 

 length of the regenerated leg was compared with the length of the original 

 leg. 



On July 17 several gammarus were taken from the lake in about the 

 same place as before. They were put in separate dishes partially filled 

 with lake water. The water was changed daily and the animals were fed 

 every five days. One day after the moult either the right bind leg or the 

 two pairs of hind legs were removed. The removed legs were mounted in 

 glycerine. Two days after the second moult each animal was killed in 

 eighty-five per cent, alcohol. The right hind leg was removed and meas- 

 ured as before. The length of the regenerated right hind leg was com- 

 pared with the length of the original leg. 



