662 THE’ AMERICAN NATURALIST. | [Vor. XXXIX. 
of development, and only one started immediately. How shall 
we account for the uneven rates of growth noticed in one or two 
eggs afterwards, for instance on the day when 2 did not grow at 
all, and the others grew twice their usual daytime amount ? 
What caused f to lie apparently quiescent for several days, then 
omit the terrace state, or cut it down to a ten or twelve hours 
at most, instead of the thirty-six to forty-eight it generally lasts 
and then growing with a leap, outstrip its brothers c and d, and 
finally even 2? The eggs were all kept under identical condi- 
tions, and the most marked variations were in those in the same 
dish. It would seem impossible for external conditions to affect 
one without affecting all the others, yet here were decided varia- 
tions in a process generally much more uniform. 
