plications. Previously, the offspring’s 
voracious appetite was confined to the 
consumption of the egg-forming 
plantlet, which lived independently of 
maternal nutrition. With the embryo 
growing in the mother’s body, what 
was to prevent digestive incursions 
into maternal tissue while still per- 
mitting protection and measured sus- 
tenance? 
I suggest that in the flowering 
plants, the solution was a “trust fund” 
established by the mother. The evo- 
lution of a nutritional intermediary, 
the endosperm, provided a zone of 
neutrality between the rich vascular 
supply of the mother and the omniv- 
orous proclivities of the embryo. With 
this interposed tissue, the offspring 
never feeds directly on the mother’s 
vascular supply. The extent of 
endosperm formation defines the nu- 
trition of the embryo. The mother’s 
final measure of control lies in the 
imposition of dormancy through the 
agency of abscissic acid. This hormone 
precisely regulates the digestion of 
endosperm and the storage of proteins 
and starch in the cotyledons, insuring 
that the funds of the mother’s trust 
are properly spent in preparation for 
dispersal. With the water content of 
the seed dropping, the embryo des- 
iccates and the surrounding seed coat 
hardens. Weaning is complete. 
To heighten the narrative line of 
my essay, I have cast the characters 
of this evolutionary drama in stark 
roles of conflict and employed a script 
filled with a language of intent and 
purpose. In contrasting the interests 
of mother and young, I have implied 
that the embryo gained no advantage 
from the development of maternal 
control over nutrition and dormancy. 
The evolution of the modern seed was 
undoubtedly more complicated than 
this. For one thing, every successful 
offspring must become a parent itself. 
If it possessed paternal genes that 
caused it to feed too greedily as a 
child, the plant would eventually face 
similar demands from those of its 
progeny that inherited the genes. Per- 
haps this explains the evolutionary res- 
olution of the conflict in favor of ma- 
ternal control over nutrition and 
dormancy. We may never know. As 
always with evolutionary speculation 
about the past, we are forced to re- 
construct history from its diminishing 
echo. 
Robert E. Cook is associate professor 
of biology at Harvard University. 
MistThat Thunders 
Niagara Falls Ontario 
Niagara. The very name evokes romance. Ride the ‘Maid of the Mist'. Feel the 
earth shake beneath you, feel the spray like a tropical rain. Try a second 
honeymoon, this autumn. 
Canada 
SO MUCH TO GO FOR 
For information, call us collect (416) 965-4008 Or see a Travel Agent 
for every lover of Americana ... a Collector’s Treasure for the entire family 
World Famous MCGUFFEY’S READERS 
seven books that shaped a nation 
Not just the primer— but the full set 
from primer through sixth grade . . , 
faithfully reproduced from the orig- 
inal engravingsl Here are the books 
our great-grandparents used in that 
one-room schoolhouse. No fancy 
theories, no newfangled nonsense, 
no educational experiments— 
McGuffey's Readers mean business! 
(Could be that's why kids learned 
their 3 R's in those days!) Yes, 
first published in 1871, these 
books were the backbone of 
Readin', flitirT, and Rithmetic! 
A fabulous acquisition for the 
serious collector. A joy for the 
whole family. Grandparents, 
Mom, Dad, kids . . . everyone will 
love a nostalgic look at this less 
complicated time, the gentle charm 
of the illustrations, the old fash- 
ioned simplicity of the texts. Truly 
a cherished gift. 
McGuffey’s Readers (Z621730) 
Complete Set of All 7 Books 
ONLY $24 g 5 
YOUR UNCONDITIONAL GUARANTEE 
Our merchandise is unconditionally 
guaranteed to please you in every way 
or your purchase price refunded— no 
questions asked! 
New Hampton 1 
General Store 
340 Poplar St., Hanover, PA 17331 
L 
from original engravings 
M mm mm ^m ^m mm mm mmm mm mm m 
New Hampton General Store, Dept bz-8065 
340 Poplar St., Hanover, PA 17331 
Please send Set(s) of All 7 McGuffey's Readers 
(Z621730) @ $24.95 per set plus $2 25 postage and han- 
dling on FULL MONEY BACK GUARANTEE 
□ GIFT SAVINGS! Order Two (2) Sets (one for yourself, 
one as an unforgettable gift), just $45.00 plus $4 00 
postage and handling. 
Enclosed is $ (PA residents add sales tax) 
CHARGE IT: 
□ American Express □ Diners Club 
□ VISA/BankAmericard □ Carte Blanche 
□ Master Charge Interbank No 
Acc't. No Exp Date 
PRINT NAME 
ADDRESS 
CITY STATE Z I P 
□ Check here ond send S0< for yeor's subscription to our full-color 
cofolog of fine gifts, (Z618314X). We ship within forty. eight 
hours; delays notified promptly. Delivery guaranteed within si*fv 
doys. 
© New Hompfon General Store 1981 
35 
