7 
this horaono in different fr**-mrtiii« of Ur- sarsa else and In t! oj© 
of different iiswo arc;- (a) Tits : •* initiation of her? r.a xiion# 
which .n turn (i«j ods on ti :» of hormone production • r» the r:l« eo- 
twin# 7p on ti~e of cor:emotion of phe rt-*l va«cuior sm- loses!c. 
(b) The leni t of 1 :»G tba hormone b*ts$ bean acting, just os in the 
r *c r^al c.,Xe, -hero tine is* t factor in the state cf the ducte, otc.* 
at an/ sta^e» but with a v&riublo condition of too organa upon e iofc 
it has to begin action. 
(4 } In all cases oh.-: rvod. ti e action of this hormone on the 
organ© ( >roductio 1 k lied to orgfr: t MMOi* tail origin* 
aitd fails to affect, those of ontoderoal origin, except, perhaps, to 
cause lightly earlier appe ranee of para~urethr.il ducts• * ich, 
owever# arc net sale in type, tout definitely fe ai», xtornel ;erl- 
kla«_ iu.al imi .-.i rvod, are uoaff Ot i stale d I 
though it if: not lost right cf, that son© such nodifie&tic- 5 ero 
described by ot; r cbe rvorc» it is b©l I ovoo: that they *&ay well be 
of sy otic ori. it? ar.i not due to nale hornone ixetior in uterine lif- • 
uch 'rrcdificaticn; ac • ear in sir: le-bom individuals, art are there¬ 
fore to bo expected in about the sane properties 5; sujeng two-sc re 
twins, whether wit cor&one action or without. 
The u; parent p^oificity in tho her-nene action is due to 
specific reactions of *-he ti-;s‘ M affected, in -but eoae arc 
sticsilat^d to incr :a e.j oveXopaent and differentiation by it, 
while others are inhibited cr-» cause : tc de.en-rate# and still 
others apj^esir unaffected. The chn--. v or; in or. ral body slap note 
la free-a&rtisa# and in equivalent organs in th 5 two sexes, in w .ich 
the fr o-®artina ro.-.e • ble c.’sles aonsatut, *©uld show that other parts 
beside sox—organs arc affected differentially. If th or ^ are part© 
unaffected# they nay ell fc cy otically controlled or past a critical 
