14 C. V. MORR1LL, JR. 



tion of the rays, and the rays themselves were fewer in number 

 than in normal fins. This result was due to very close cut- 

 ting ; entire rays were removed in some places, and in others, 

 where stumps remained an alteration in direction of these stumps 

 occurred in some way when the wound healed over. In one 

 case the new fin grew straight out in the normal direction but at 

 different rates of growth in different parts so that it presented a 

 finger-like appearance. This abnormality was probably due to 

 a jagged cut, the fin-rays being disarticulated in some places 

 while in others, the stumps were left in situ. In still another 

 fish no regeneration took place at all although the wound healed 

 over smoothly. This fish was kept under observation four 

 months. Here the cut probably either disarticulated the rays or 

 left too small a stump for regrowth to take place. 



On January 9, 1906, the tails of twenty-four fish were cut off 

 in such a way as to remove a portion of the body of the fish, 

 including several vertebrae. Obviously this operation was ex- 

 tremely severe. These fish when returned to water were unable 

 to assume a horizontal position but remained head downward at 

 the top of the tank. Three days later eleven were still living. 

 These latter had succeeded finally in reaching the bottom of the 

 tank and some were swimming about in a nearly normal position. 

 At this time, January 12, another set of twenty-four fish, cut as 

 described above, were put into the same tank with the eleven 

 just mentioned. Three days later only seventeen were left of the 

 entire number, thirty-five. This number gradually decreased 

 until the entire lot died within a month's time. 



Another set of twenty-four were cut in the same way but it 

 was found impossible to keep them alive. The wounds remained 

 open and the flesh rotted away from the sides of the vertebrae. 



In the above sets, various sizes of fish were used. In still 

 another set ten small fish were employed and -kept in shallow 

 dishes in the laboratory in order that they might assume a hori- 

 zontal position. Within a month all of these had died with one 

 exception. This might have been due to unfavorable conditions 

 in part, though I have kept fish living in these shallow dishes 

 over three months. In the exception noted, the wound had 

 healed over smoothly and a very small white knob of tissue ap- 



