5. The following misprints have been corrected: "Ned" corrected to "Neb" (page 13) "cruciferae" corrected to "cruciferæ" (page 25) "thoughfully" corrected to "thoughtfully" (page 182) "pronouced" corrected to "pronounced" (page 199) "resoved" corrected to "resolved" (page 205) 6. Other than the corrections listed above, printer's inconsistencies in spelling, punctuation and hyphenation have been retained.