262 
STATE AGRICULTUEAL SOCIETY. 
of animals and plants; but it is absolutely necessary, for its 
proper performance, that each step of the process should be 
performed, and in itself complete, before the next takes place. 
That the performance of this function makes great demands 
upon the nutrition of the parent, is of such common knowl¬ 
edge that it is only necessary, here, to refer to the length of 
time expended in the preparation of the body of the parent, 
for its maturity, before the function is called into action; in 
other words, until it shall be capable of bearing young. 
When the germ is not formed* from the parent stock, the 
condition is that of barrenness or sterility. 
If the parent is unable, from any cause, to furnish the proper 
materials for the maintenance of the germ, after fecundation, 
during the second of the reproductive processes, or that of 
development; or if, for any reason, either external or internal, 
the process furnishing the supply is interfered with, this devel¬ 
opment is arrested. This arrest may be complete or partial; 
if complete, the germ dies, it is cast off as a foreign substance, 
and an abortion is said to occur; if the arrest is partial, a so- 
called deformity of some part is the usual consequence. 
The methods by which the germ is nourished after concep¬ 
tion, and before its birth, differ widely in different species of 
animals. The oviparous animals cast off the germ with its 
supply of nourishment, as an egg, to depend, perhap;!, upon 
other external sources to furnish the conditions necessary to 
its development; the so-called parent not necessarily supplying 
any of the nutritive material. The viviparous animals retain 
the germ, attached to the parent, during the second period of 
its development, and until it is able to take on an inde¬ 
pendent existence. This connection in the truly viviparous 
animals is most intimate, the foetus depending entirely upon 
the parent for its nutritive supply ; and as it increases in size 
and multiplicity of parts, making continuously greater 
demands for the materials necessary to its growth ; which in all 
cases are furnished more or less directly from the hlood of the darn. 
Further differences exist even among viviparous animals in 
the arrangement of the parts concerned in the reproductive ap- 
