EB Er 
in the dunes of North-Jutland, are purely female, and these specimens 
always stand on very dry places and were, taken as a whole, 
smaller than the common hermaphrodite ones. Further a patch 
of H. pilosella in a dry lawn in the Botanical Garden gave only 
female flower-heads in the last autumn; one of thesé heads has 
been figured on the Plate (fig.8) and will show, that it is smaller 
and paler than a head of the normal H. pilosella (fig. >). 
It is likely from the cases here mentioned, that the sexuality 
of some Hieracium-species under certain external circumstances 
can be weakened. And perhaps it may be supposed that the apo- 
gamy is a provision against this accident. Were the suppression 
of the pollen-grains has become normal (f. i. H. excellens), the plant 
has been able to produce at least a great many of its fruits 
without fertilisation. A fact which may be of some interest is, 
that both H. excellens and H. roxolanicum originate from Galizia, 
and that I last year in Hungary (Herculesbad) collected seeds of 
two Piloselloidea, which now, when flowering, show, that they 
are both female; the one is a form of H. magyaricum, the other 
belongs to the species with so-called dichotomous scapes; it then 
seems as if the female forms were more common in the S. E. part 
of Central-Europe. 
The report given here will, it is to be hoped, show, that the 
Hieracia offer a great many interesting problems, and that some of 
them bear an interest reaching far beyond the genus, but it will 
also show, that at present we are only in the mere beginning of 
our knowledge about these phenomena. I hope in further reports 
to be able to explain several questions which now are unsolved, 
but there are more problems here than one single man can 
take up. — 
I cannot end this paper without expressing my best thanks 
to the Director of our Botanical Gardens, Professor, Dr. E. War- 
ming, and to our Garden-inspector Mr. A. Lange for their kind- 
ness in placing a part of the garden at my disposal for these 
experiments and in helping me in all possible ways. And finally 
I have to acknowlegde my debt of gratitude to Professor W. 
Bateson, of Cambridge, who has kindly corrected the grammar 
and vocabulary of the English. 
Copenhagen, July 1906. 
