No. 4.] Reprints. 226 



freed from eggs, so that the exact date of deposition was assured. 

 The eggs were tested every day. 



On the day of collection (first day) the eggs appeared immature. 

 One day later eight eggs opened by picking the operculum off 

 showed three larvae with slight movement, and five immovable. 

 On the third day a half hour of friction failed to hatch eggs, 

 but the larvae when freed by picking off the operculum showed 

 two, slight movement ; one, no movement, and one sufficient move- 

 ment to get out of the opened shell. 



On the fourth day the larvae in eleven eggs were all active, but 

 had to be freed by picking off the operculum ; the same was true up 

 to the seventh day, the only difference being noted in greater 

 maturity and size of larvae. 



On the ninth day, or when the larvae were eight days from 

 deposition, one larva was freed by seventeen minutes of rubbing 

 with wet finger, another in twenty-two minutes ; on the tenth day 

 two others, one in fourteen and the other in eight minutes ; and on 

 the eleventh day several were hatched, the time varying from two to 

 five minutes of subjection to the saliva and friction. On the twelfth 

 day it required but one or two minutes, and on the thirteenth eggs 

 would hatch in fifteen to thirty seconds. On the fourteenth day a 

 number of eggs were tried, about one-third of which hatched almost 

 immediately upon being touched with the moist finger, the others in 

 from five to eight seconds. On the fifteenth day all eggs seemed 

 fully mature, and probably nine-tenths would have hatched at once 

 upon being touched by a horse's tongue in the ordinary motion of 

 licking. From the sixteenth day to the twenty-second the eggs 

 would open with a touch of the finger, but the larvae would not ad- 

 here except with moisture. On the twenty-third day the first dead 

 larva was noted, and a day later four out of eleven eggs opened had 

 dead larvae. On the twenty-fourth day all of the eggs not previously 

 opened were examined with a lens, and only one showed the cap re- 

 moved, the larva being partly out, but dead. The hatching of but 

 one egg out of three hundred seems to me to establish pretty fully 

 my former opinion, that the eggs require moisture or friction for 

 the release of the young. 



On the twenty-fifth day, out of ten eggs three contained dead larvae, 

 five could move slightly, and two were quite active. On the twenty- 

 sixth day caps were removed from thirty-five eggs, twenty-seven 

 larvae being dead, seven were capable of slight movement, and one 

 was active enough to escape from the shell. 



