Additional Notes. &0^ 



Towards the close of the seventeentli century some atten- 

 tion liad been paid to the different kinds of hairs which con- 

 stitute a downy covering upon tlie surfaces of vegetables. 

 But it was not till the year 1745 that this subject was treated 

 in the full and masterly manner that it deserved. In tliat 

 year M. J. Stephen Guettard, a very ingenious and 

 learned French botanist, began to publish his observations 

 on the hairs and glands of plants. These observations he 

 continued during several succeeding years. He has even esta- 

 blished a botanical Method^ deduced from the form, the si- 

 tuation, and other circumstances of the hairy and other glan- 

 dular appearances on the surface of plants. He has shown 

 what, perhaps, would hardly have been suspected, that these 

 appearances are, in general, constant and uniform in all the 

 plants of the same family or genus. Hence, he has observed 

 that they constitute good generic, but not specific characters. 

 • — Bartot^'5 Elements of Botany. 



Sir John Hill, after much inquiry in vegetable physiology, 

 published, in 1773, a very extensive work, which has been com- 

 monly called his Vegetable System , in which he proposes a me- 

 thod of arrangement founded on the ijiferjial st rue tio^e of phnts. 

 About the same time, M. Tillet, of France, and the cele- 

 brated Spallanzant, of Italy, published the results of their 

 observations and experiments on the organs and functions of 

 vegetables, which have been generally considered as highly 

 valuable. Besides what has been done by these naturalists, 

 new light has been thrown on vegetable physiology by Pro- 

 fessor Walker and Dr. Darwin, of Great-Britain; by 

 Des Fontaines and Vauquelin, of France; by Ponte- 

 DERA, of Italy; by Sennebier, and Saussure, senior and 

 junior, of Geneva; and by Plenck and Reichel, of Ger- 

 many. 



But among the vegetable anatomists and physiologists who 

 flourished towai'ds the close of the eighteenth century, Jcseph 

 G-ERTNer, of Germany, deserves particular distinction. Thi.'; 

 great botanist was born in the year 1732, and died in 179LJ. 

 at the age of 59. He early devoted himself to x\\q fruit of 

 vegetables, not only as a part of vegetable physiology which 

 liad been too much neglected, but also as furnishing one of ciie 

 best grounds of botanical arrangement. A method of tiiis kind 

 lie exhibited in his great work, De Fritctii)us et Scminibus 

 Plantarum, the first volume of which was puhlislicd in 17S8, 

 and the second in 1791 : a work which abounds witli valua- 

 ble instruction In botanical science; and though tlie method 



