An Experimental Study of Somatic Modifications etc. 
325 
been constructed for the later offspring of the same parents. These 
latter curves are based upon measurements made at the same age 
(6 weeks), but they do not, like the foregoing, represent differences 
produced during the induvidual lifetime. 
The relative modifiability of tail, foot and ear are clearly shown 
in the present diagrams (3 and 4), though it must be borne in mind 
^ 9 10 i1 12 13 14 15 16 17 18 iD 20 21 22 
Curves representiDg tail length., at 42 days, of another lot of mice (first offspring of those represented 
in Fig. 2), which have been subjected to similar differences of temperature. For further explanation, 
see preceding figure. 
that the scale for the two last characters is five times as great as 
that for the tail. 
tive effect was sought for. Reference to the temperature chart (Fig. 1) shows 
ns, however, that after the middle of March, when these second-generation mice 
were born, the temperature differences between the two rooms diminished 
rapidly. Thus the offspring were subjected to decidedly smaller differences 
than were the parents; and under these circumstances we could hardly hope 
to discover any cumulative effect. As a matter of fact, the figures, though in- 
conclusive, are favorable, rather than contradictory, to the hypothesis of trans- 
mission. They will not, however, be presented here. 
