Bios 
been interpreted as a single, integrated 
process marked by cooperation be- 
tween parent and offspring. A grain 
of pollen alights on the tip of a flower 
and begins to grow slowly down the 
stalk. Once the pollen reaches the 
ovary, its two male nuclei, each with 
half the genes of the father, enter 
the embryo sac and seek fusion with 
maternal nuclei. The rapid cell divi- 
sion that results from the union of 
one paternal nucleus with two or more 
maternal nuclei produces endosperm 
tissue, which is fed by the proliferating 
vascular structure of the adjacent 
ovular wall. The other paternal nu- 
cleus fuses with another maternal nu- 
cleus to create a zygote, or fertilized 
egg cell, which gradually commences 
growth. After numerous cell divisions, 
this embryo has developed two grow- 
ing tips and one or two incipient leaf- 
like cotyledons for the storage of nu- 
trients. Rather than coming directly 
from the mother, much of the energy 
for the growing offspring comes at 
the expense of the endosperm. This 
tissue may be rapidly expanding close 
to the vascular supply while being di- 
gested by the embryo a short distance 
away. (In some species, such as beans 
and peas, the offspring eventually con- 
sumes all of the endosperm and oc- 
cupies most of the future seed.) 
Gradually, the growth of the seed be- 
gins to slow down, the water content 
drops, and the outer coat hardens. Ac- 
cording to this traditional view, the 
future seedling becomes dormant in 
preparation for dispersal; germination 
will occur later upon rehydration of 
the seed. 
But is a phase of dormancy really 
necessary for proper seedling devel- 
opment? Ian Sussex, a developmental 
biologist at Yale University, and his 
students have suggested an alternative 
interpretation of seed development, 
which suggests that the roles of the 
mother and the offspring are some- 
what in conflict. They see the for- 
mation of a new individual — from a 
fertilized egg to a growing, rooted 
shoot — as a potentially continuous de- 
AMATEUR’S 
GUIDE TO 
ARCHAEOLOGY 
IN THE t 
UNITED *■* 
STATES 
JOSLEEN 
WILSON 
COLLIER BOOKS 
A division of 
Macmillan 
Publishing 
Co., Inc. 
MACMILLAN 
Take a different kind of vacation — 
into America's past! 
With this wonderfully rich paper- 
back guide, you can goon a dig. . .visit 
excavations. . .see special museum 
collections. ..join other interested 
amateurs who tour regularly. 
All of the information you need to 
enjoy such fascinating adventures is 
assembled in one concise volume 
that's written so engagingly, even arm- 
chair adventurers will find it delightful. 
State-by-state coverage of sites and 
museums, travel directions, 
admission-fee data, hours, photos, 
maps, charts — all of it is here, to 
help you explore the extraordinary 
legacy of America's past. 
THE PASSIONATE AMATEUR'S 
GUIDE TO ARCHAEOLOGY IN THE 
UNITED STATES 
Enclosed please find $ for 
copy(ies)(§ $12.95 each, plus 
$1 .50 for each book for postage and 
handling. I understand that it I am not 
completely satisfied, I may return my 
purchase wi 
rithin 15 days for a full refund. 
Address 
State 
098670-X/IC#093 
Mail to: 
COLLIER BOOKS, Macmillan Publishing 
Co., Inc. 100K Brown Street, Riverside, 
N) 08370 NH 
Please add appropriate state and local taxes. 
Write us at Tourism British Columbia. 1 1 1 7 Wharf St . Victoria, B C V8W 2Z2 Or see a Travel Agent 
Rocky Mountain High 
Purcell Range British ( 
Superlative autumn scenery. Mountains, fjords, glaciers and waterfalls. 
Countless rivers and coastal streams. Totem poles overseeing all, from 
hidden places. Come on up. 
British Columbia 
Canada 
SO MUCH TO GO FOR 
31 
