706 ANNUAL REPORT SMITHSONIAN INSTITUTION, 1907. 
by differences in the structure of the corolla. The Linnean classes 
were very much more easily learned than the Tournefortian. His 
Class I embraced all genera of plants the flowers of which have but a 
single stamen; Class II those which have two stamens, and so on up 
to Class X, when other considerations,-still in part numerical, were 
seized upon. Any mere beginner in botany, with a plant in flower 
before him, could determine its class without even opening the book. 
If the flower exhibited five stamens the plant was sure to belong to 
some genus of Linnzeus’s Class V. If the same flower showed also 
two pistils, that indicated as unmistakably Order 2 of Class V.. No 
other system of plant classification ever invented made the beginnings 
of botany so easy; no other ever was so immensely popular. But 
what is much more to the credit of the Linnean classes and orders 
than the popular applause with which they once were hailed is the fact 
that the determination of plants under them necessitated close inspec- 
tion of all, even the minutest and obscurest parts of every floral 
structure, trusting that in these minute, obscure, and hitherto neg- 
lected organs there would be found some of the very best indexes of 
affinity. This line of investigation, so important to all taxonomy, 
Linneeus was the very first to carry into practice and make universal. 
It will be difficult to bring the average botanist of to-day to a realiza- 
tion of how great an epoch in botany Linnzus created when he began 
examining the stamens of every plant, with the purpose of ascertain- 
ing into what one of his 23 proposed classes of flowering plants each 
generic type must fall. And though it be true that the classes and 
orders of Linnzeus fell into disuse three-quarters of a century ago, it 1s 
true to-day that every botanist, from the mere beginner in taxonomy 
to the most accomplished master of it, if he have a new and unknown 
plant in hand for determination, makes his final appeal to stamens 
and pistils. These, by peculiarities of structure, will tell the plant’s 
relationship in many an instance, both promptly and decisively. In 
this procedure every botanist who lives is distinctly a disciple of 
Linneus; for he, putting Vaillant’s principles into taxonomic prac- 
tice, first inaugurated the method, and eventually brought to pass its 
universal recognition and its permanent establishment. 
When in the year 1735, with those manuscripts of his new botanical 
system, Linnzus went to Germany and Holland, he had now for 
seven years been scrutinizing carefully and industriously the stamens 
of everything that had come to hand. By dint of those seven years of 
industrious investigation of these organs he had not only become 
very expert in this line, but he was the only man in the world who 
knew anything about the morphology of stamens. He was now, to the 
oldest and most experienced systematists of Europe, a perfect marvel 
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