ACKNOWLEDGMENTS. 



The author would express his thanks to his friend Dr. 

 Peter Collier, Professor of Chemistry in the University 

 of Vermont, for a large share of the calculations and re 

 ductions required for the Tables pp. 150-6. 



Of the illustrations, fig s 3, 4, 5, 7, 47, 63, and 64, were 

 drawn by Mr. Lockwood Sanford, the engraver. For oth 

 ers, acknowledgments are due to the following authors, 

 from whose works they have been borrowed, viz. : 



SOHLEIDEN. Fig s 10, 13, 17, 19, 30, 48, 49, and 50, 

 Physiologic der Pflanzen und Thicre. 



SACHS. Fig s 56 and 65, Silztmgsberichte der Wiener 

 Akademie, XXXVII, 1859, and fig s 22, 38, 40, 41, 42, 

 43, 59, 66, 69, 70, and 71, Experimental-Physiologie der 

 Pflanzen. 



PAYEN. Fig s* 11, 12, and 23, Precis de Chimie Tndut- 

 trielle. 



DUCHARTRE. Fig s 60 and 61, Elements de Botanique. 



KiiHN. Fig s 18, 21a, 29, and 34, Ernahrung des 

 Rindviehes. 



HARTIG. Fig s 20, 21b, 32, Entwickelungsgeschichte 

 des Pflanzenkeims. 



UNGER. Fig. 26, Sitzungsberichte der Wiener Akade- 

 mie, XLIII, and fig. 55, Anat. u. Phys. der Pflanzen. 



SCHACHT. Fig s 33, 37, 44, Anatomic der Gewmchse, 

 fig s 51, 53, 54, and 62, Der Bourn, and fig s 52, 57, and 

 58, Die IZartoffel und ihre Krankheiten. 



HENFREY. Fig s 36 and 39, Jour. Hoy. Ag. Soe, of 

 England, Vol. XIX, pp. 483 and 484. 

 7 



