68 
the Alpine specimen. We may be justified in connecting this 
tendency toward self-pollination with the scarcity of insects in 
the country in question. It will facilitate self-pollination if the 
interior of the corolla by its covering of hairs is able to gather 
up the pollen grains and retain them as mentioned above. 
Some species appear to me to. be less well-adapted for 
self-pollinalion, especially of Ledum and Rhododendron. The 
former with its richly-flowering inflorescence recalls somewhat 
that of the Umbellifere, and geitonogamy must evidently be 
able to take place easily in it. 
All the flowers are for the most part homogamous for a 
long period, but some begin by being protogynous for a short 
time (Arctostaphylos alpina, Cassiope hypnoides, Ledum, Phyl- 
lodoce, Loiseleuria, Rhododendron) and others protandrous, also 
for a short time (Cassiope tetragona, Vaccinium Myrtillus, V. 
Oxycoccos, V. uliginosum, V. Vitis-ideea). 
Probably self-pollination sometimes takes place before the 
flower opens, so that a kind of cleistogamy occurs, because 
as has been mentioned, the anthers generally open while still 
in the bud, and in some cases, I even found the pollen shed 
(Arctostaphylos Uva-ursi). 1 found the anthers dehisced, and 
fully developed pollen grains lying loose in the buds in this 
species and in the following: Cassiope tetragona, C. hypnoides, 
Andromeda polifolia, Leduin palustre, Vaccinium Vitis-idea, 
V. uliginosum, V. Oxycoccos, Lyonia, as also in Erica Tetralix, 
E. cinerea and Calluna vulgaris. In. the greater number of 
these species I also found that the stigma in the bud was 
viscid and capable of retaining the pollen, or was at least able 
to do so in flowers which had just expanded. In a greenhouse 
in Copenhagen, in a flower of Lyonia not yet expanded, I found 
pollen upon the stigma. In Finmark, in a bud of Cassiope 
tetragona, | found the stigma viscid and the anthers open; the 
pollen could not however fall out, but did so immediately that 
the anthers became dry after the expansion of the bud. This 
