220 Mary I sab ell e Steele 



is probable, however, that they would have increased both in 

 diameter and length had the experiment covered a longer period 

 of time. None were distinguishable before the occurrence of a 

 moult. In each case recorded the appendage appeared after the 

 first moult. Most of these appendages were definitely segmented 

 after the first moult, in some instances several segments being 

 developed within twenty-one or two days. But none show any 

 indication of being divided into parts corresponding to the exo- 

 and endopodites. 



Figs. 23 and 30 show two appendages that were present twenty- 

 one and twenty-two days respectively after the injury. Neither 

 appendage exceeds in length the squame at the base of the normal 

 eye stalk which measures but little more than one-fourth of the 

 whole length of the normal stalk. One appendage bears a con- 

 siderable number of large tubular hairs. The other shows none 

 whatever. Each is seen to consist of several segments. Five 

 segments are distinctly visible in Fig. 23 while in Fig. 30 there are 

 six or seven though they are not distinctly differentiated. In Fig. 

 30 the appendage projects outward at a broad angle. Fig. 23 is 

 unique in that it curves in toward the median line and suggests in 

 its general shape and position the squame at the base of the 

 opposite eye. The bifid tip of this appendage is probably due to 

 some injury that occurred at the time of the moult. This explan- 

 ation is suggested by an examination of the specimen. 



Figs. 34 and 45 represent two other appendages that appeared 

 twenty-nine and thirty-two days, respectively, after the injury. 

 These types differ somewhat from the preceding two. It is to be 

 noted in both cases that the original operation did not include the 

 squame at the base of the eye. This is a good indication that at 

 least a part of the proximal segment of the optic ganglion was left. 

 The specimen shown in Fig. 34 was sufficiently transparent so that 

 the optic nerve could be observed extending into the base of the 

 segmented appendage. The specimen from which Fig. 45 was 

 taken was fixed in Flemming and the consequent darkening of the 

 tissues prevented an accurate determination of the length of the 

 stump of the optic nerve. But the nerve stump could be seen 

 extending well into the base of the new appendage. 



