24 SCANDINAVIANS AND 
Hans Baltzar Hornbeck was born the 9th of January, 1800, 
at Copenhagen. In 1829 he took his chirurgical examination, 
and went out the same year as ship-surgeon on the government 
vessel “‘Diana’’, to the West Indies. Two years later he took his 
examination as doctor of medicineand moved to St. Johnas prac- 
ticing physician. He returned to Denmark in 1844, and died in 
i He was an ardent collector, and corresponded much with 
Prof, Schouw in Copenhagen. 
Johan Emanuel Wikstroém was born at Venersborg, Sweden, the 
1st of November, 1789, became doctor of medicine in 1817, and 
was director of the Botanical Museum at Stockholm in1818—’56. 
He died the 4th of May, 1856. For many years he published 
“Ofversigt af Svenska Vetenskapsakademiens handlingar.’’ There 
are numerous publications from his hand, but only the following, 
as far as the writer knows, refer to American botany. They were 
principally based on the collections made by Dr. Fahlberg, Eu- 
phrasen, Richard, l’Herminier, Bertero, and Forstrém. 
Ofversigt af én Sanct Barthelemis flora (6 new species), 1826. 
Ofversigt af 6n Guadeloupes flora (21 new species), 1828. 
Enumeration of Plants of St Eustache and Saba. 
Den amerikanska Agaves eller den s& kallade hundraariga aloens natural- 
historia. 
6. HOOKERIAN PERIOD, 1840—1889. 
The appearance of Hooker’s Flora Boreali-Americana, 1829—'40, and about 
the same time of Torrey and Gray’s Flora of North America, 1838—’43, marks the 
beginning or rather the end of a period, at least as far as North American botany 
is concerned. These two books represent the work done during the Candollean 
period of two decennia of most active work. The new period was also an active 
one, for during this were undertaken the botanical explorations connected with 
the Mexican boundary survey, the Pacific Railroad surveys and Hayden’s geolog- 
ical surveys. Nuttall,Torrey, and Engelmann were still at work during the earlier 
part. C.C. Parry, Hall and Harbour, Bigelow, Watson, Thurber, Wolf, Porter, 
Coulter, Palmer, Brandegee, Lemmon, Bolander, Kellogg, Greene, ete., were eX- 
ploring the West; Palmer and Pringle began their work in Mexico, and the Ma- 
couns, father and son, theirs in Canada. The systematic part, at least on the 
flowering plants, passed over almost exclusively to one institution, viz. Harvard, 
Gray was the leading spirit. 
Bentham and Hooker’s Genera Plantarum, in which was inaugurated mod- 
ifications and improvements on the Candollean system of classification, appeared 
about the middle of this period, 1862—’83. It would hardly be advisable to as- 
_ Sign as the beginning of a new period the time when this appeared; for the “Ben- 
tham-Hookerian system” differs in no essential respect from that of De Candolle 
