1884. ] Growth, its Conditions and Variations. 1089 
are well adapted to procure food in the mature stage, as in ants, 
the reproductive powers fail to develop at all, except in one or a 
few members of the tribe, while individual life may be continued 
for years. 
The opposition between these two powers is clearly displayed 
in other cases. Wherever nutriment is abundant and easily ob- 
tainable individual life at once gains an advantage over race life. 
The reproductive period is retarded. But if nutriment become 
deficient reproduction is hastened. This has been fully proved 
by experiments on plants, which, if abundantly fed, grow pro- 
fusely in leaves and branches, but delay flowering. But if sub- 
jected to a starvation process they flower early, and remain 
stunted individually. Instances of the same kind may be ob- 
served in animals, and asa rule deficient nutrition may be said 
to cause reduction of size and early reproductive activity, while 
abundant nutrition has the opposite effect. 
In this regard an interesting conclusion may be drawn from a 
general survey of the conditions of animal life. Reproduction 
means the separation from the body of cells which are the 
epitome in structure of the whole organism. This separation 
bears a constantly decreasing relation to the bulk of the whole 
y as we ascend in the animal series. In the Protozoa the 
serm-cell takes the half of the body, or in some cases the whole 
of the body is converted into germs. In the Metazoa a lesser 
Portion of the body is shed as germs. The proportion is great 
m the lower animals, in some cases extreme, but small in the 
higher Classes, and very minute in the highest. The fact that 
the shedding of germs is hastened by deprivation of food sug- 
Sests a reason for this difference. Every higher animal is ina 
certain sense a colony of coherent cell individuals. This cohe- 
Fence is an indication that they are favorably situated for nutriti- 
tion. If food fails to come to them they will go to seek it. In 
other words, the offspring of the coherent cells will become wan- 
dering cells. This is very probably a constant effect of the 
§towth of animals, since with every increase in bulk the ability 
to supply the whole mass of cells with food decreases. In con- 
Sequence we may surmise that wandering cells are budded off 
by the fixed cells more abundantly as size increases, with the 
effect of checking the growth of the animal, and eventually of 
Preventing any further increase in bulk. 
