THE HISTORY OF ANATOMICAL SCIENCE 327 
germ-cells may remain unchanged, and become 
included in that body, which has been composed 
of their metamorphosed and diversely combined 
or confluent brethren ; so included, any derivative 
germ-cell, or the nucleus of such, may commence 
and repeat the same processes of growth by imbi- 
bition, and of propagation by spontaneous fission, 
as those to which itself owed its origin ; followed 
by metamorphoses and combinations of the germ 
masses so produced which concur to the develop- 
ment of another individual ; and this may be, or 
may not be, like that individual in which the 
secondary germ-cell or germ-mass was included. 
Again (p. 72) 
‘ It would be needless to multiply the illustra- 
tions of the essential condition of these pheno- 
mena. That condition is, the retention of certain 
of the progeny of the primary impregnated germ- 
cell, or, in other words, of the germ-mass, un- 
changed in the body of the first individual 
developed from that germ-mass, with so much of 
the spermatic force inherited by the retained 
germ-cells from the parent cell or germ-vesicle as 
suffices to set on foot and maintain the same 
series of formative actions as those which consti- 
tuted the individual containing them. 
‘ How the retained spermatic force operates 
in the formation of a new germ-mass from a 
secondary, tertiary, or quaternary derivative germ- 
cell or nucleus, I do not profess to explain ; 
