93e. — 
planted into a larger pot, where they flowered in September. Sep- 
tember 3rd—5th; 11 heads were castrated, but did not give any 
developed fruit. The intact heads gave, but sparingly, ripe fruits 
(553 barren to 215 full); the full fruits have germinated in the 
spring of 1906. As the plants stand in a closed cold-house, no 
cross-fertilisation has happened. 
(3) H. auricula L. (s. 1.); specimens transplanted to the Bo- 
tanical Garden from the northern part of Jutland (Skagens Odde, leg. 
M. L. Mortensen). July 9! 1905; 7 heads were castrated, but the 
heads all faded; also later castrations did not succeed. The intact 
heads gave ripe fruits, rather copiously, except in the late autumn, 
when nearly all fruits were barren. 
(4) H. sp., labelled H. lactaris, according to Mr. Dahlstedt 
belonging te the group of H. umbellatum; growing in the Hieracium- 
plot in the Garden. August 14th—15th; 7 heads (the only remaining 
ones, the main flowering period being over and ripe seeds developed) 
were castrated, but none gave full fruits. 
(5) A. umbellatum L., f. filifolium, growing together with the 
foregoing species. Also of this form some few (10) unopened, late- 
developed heads were castrated in August and September, but 
without any positive result. 
(6) H. umbellatum L. f. dunense (revis. H. Dahlstedt); wild- 
growing specimens. The experiments were carried out in the dunes 
of North-Jutland near Tveersted and on specimens growing in their 
natural places. The plants were very common in the dunes and 
gave ripe and full fruits in abundance. July 25th—96th 1905; 9 
heads, belonging to three individuals, were castrated; some of the 
heads began to develop, others faded in course of a week. As I 
had to leave the place about a fortnight after, the experiments 
were broken off August 5t; the half-developed heads were preserved 
in alcohol and later examined thoroughly. It then appeared, that 
the ovule had grown to a certain point, but no embryo was 
formed; we are therefore justified in saying that no fructification 
occurs after castration. 
(7) H. virosum Pall.; seeds obtained from the Missouri Botanical 
Gardens were sown in the spring of 1905, planted out in July, 
flowered very sparingly in September. September 3"4; two heads 
were castrated, but the one did not succeed; the other gave 36 full 
fruits (12 empty), which have germinated in the spring of 1906.— 
If we arrange the species used in experiments in 1903—05 
