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APPENDIX. 
that there was reproduction of life upon the earth long before 
either male or female existed. 
To begin, however, with the more familiar process of sexual 
generation, we know that the whole of the characters of the plant 
or animal must in some way be capable of being packed up within 
the extremely minute compass of a sperm cell and a germ cell, 
and since a spore is capable of producing both sperm cells and 
germ cells, the whole of the complex characters of a Fern, say 
Athyrium Clarissima or Lastrea montana Barnesii, must somehow 
be contained within the narrow compass of a spore. 
The ultimate male and female elements are, of course, 
the ovum or egg cell and the antherozoid or sperm cell. Of 
these the egg cell is very much the larger, but we do not 
therefore find that the offspring as a rule resemble the female 
parent much more than the male. On the other hand, the 
characters of the two parents are generally fairly equally 
balanced, and when they are unequal those of the male are just 
about as likely to preponderate as those of the female. 
The inference must be either that the hereditary substance 
is weaker in the large egg cell than in the very small sperm cell, 
or that only a small part of the egg cell consists of hereditary 
substance, the rest being merely nutritive material. There is 
abundant evidence that the latter is the case. When the sperm 
cell or antherozoid penetrates the egg cell, it takes no notice of 
the great body of the latter, but plunges through it and makes 
straight for the nucleus, with which it blends itself. We shall 
see by-and-by that there is reason tc suppose — not that the 
hereditary substance is the nucleus or the cell, but that the 
nucleus contains the hereditary substance. 
In order to make myself clear to all, 1 must go back some 
little way, and if 1 describe things which to some of you seem 
elementary, 1 trust that you will grant me your patience. 
You are all aware that every living organism — whether plant 
or animal — is built up of cells. Some of the simplest kinds, such 
as the Amoeba and Paramaecium, consist of one ceil only, while 
the great majority of kinds consist of a vast number of cells, 
which are all formed by the division and sub-division of one 
original cell, which is again formed, as 1 have stated, by the 
union of the male and female germs. The growth of plants and 
animals consists in the division and sub-division of cells. Within 
a comparatively few years, it has been observed that whenever a 
cell divides into two, a very complicated process is gone through. 
In order to make you understand this, I must describe somewhat 
minutely the anatomy of a cell. A cell consists of a small quantity 
of a jelly-like substance called protoplasm, which is enclosed in an 
extremely thin and delicate membrane. 
