THE SEQUOIA 
Columbus’ discovery of America (1492) was followed by 
Magellan’s famous trip around the world to the westward (1519- 
1522), during which he discovered the Philippines; and about 
the same time Cortez conquered Mexico. The New World was 
soon explored for its reputed hidden treasures, and astronomers’ 
search of the heavens for an orderly movement of planetary 
bodies resulted in the elaboration of the system of Copernicus 
(1543). Keppler announced his laws of planetary motion at 
about the same time (1609), and in the latter part of the seven- 
teenth century Newton enunciated the law of gravitation. The 
increasing freedom of thought was expressed in the American and 
French Revolutions. 
The rapid course of invention during the nineteenth century 
is too familiar to require detailed mention. The period of the 
tree’s growth, however, is represented by only a few inches in its 
total diameter. 
The cards representing the growth of biology are arranged in 
two groups. Those above the line of black cards represent the 
change of thought in the philosophy of biology, while those below 
the line indicate some of the great discoveries which have made 
the science what it is to-day. The latter have been divided into 
three rows, the uppermost representing General Zodlogy, the 
middle Comparative Anatomy and Paleontology, and the lowest 
series the evolution of Embryology. 
Very strikingly is it shown that not only the scientific side of 
all branches of biology, but also the philosophical or speculative 
side, has been developed during the old age of the tree, or during 
the last 300 years. In fact, modern zodlogy and inductive 
methods may be said to have begun with William Harvey in the 
seventeenth century. 
It is true that when the tree began its life, men had ideas and 
conceptions of the principles underlying nature, but most of 
these were crude and inaccurate, based on mere hearsay or tradi- 
tion, and differing but little from those held before the beginning 
of the Christian era. 
The science of anatomy had been at a standstill since the 
time of Galen (a.p. 130). This brilliant anatomist, it is true, 
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