266 
xcix., appears to be chiefly 4. campylopodum, Engeln., though 
the plate also contains figures of the European A. Uxycedri, M. 
Bieb. A good figure with dissections of the European A. Oxycedr 
is to be found in Reichb., Ic. Fl. Germ., vol. xxiv. tab. i41. 
The Tropical African locality given above is of exceptional 
interest since the plant has not previously been known to occur 
outside the Azores, the Mediterranean Region, and Western Asia. 
{The specimen was collected by Mr. W. J. Dowson on the north- 
western slopes of the Aberdare Mountains in British Hast Africa, 
at 6500 ft. altitude, growing parasitically on Juniperus procera, 
Hochst. This juniper has been fully dealt with in the Flora of 
Tropical Africa, vol. vi. Sect. 2, p. 336. It is the only species 
of the genus occurring in Tropical Africa and is widely distri- 
buted in Eritrea, Abyssinia, Somaliland, Uganda, British East 
Africa and Nyasaland. The tree is a most valuable timber tree 
in East Africa, as indicated by Hutchins, Rep. Forests on Kenia 
in Col. Rep. Misc. No. 41 (1907), p. 15. Since Arceuthobiwm is 
a parasite comparable in its effects on the host to the mistletoe 
and other Loranthaceous parasites its presence in Hast Africa may 
be of some economic importance. 
In connection with the record of Arceuthobium on the Aberdare 
- Africa. Its previously known distribution was United States and 
Russia. The geographical distribution of fungi is known often 
to be erratic, but the partial coincidence in distribution between 
the two juniper parasites Arceuthobium and Fomes juniperinus 
is interesting. 
It is well known that Arceuthobiuwm has explosive or sling 
fruits. A paper by Dr. T. MacDougal in Minnesota Botanical 
Studies, vol. ii. p. 169, 1899, deals in detail with the explosive 
mechanism of an American species. The American representa- 
tives of the genus like the Old World ones have very local and 
discontinuous distribution, and in this connection the methods 
of seed dispersal have to be carefully considered. In MacDougal’s 
paper, quoted above, it is pointed out that the only localities 
which offer suitable conditions for the germination of the seeds 
-are the tips of branches or the shoots of young trees underneath, 
and no animals are to be found in the habitat of the parasite 
which would in ordinary usage carry the seeds to these locations. 
Studies in Northern Arizona showed that the distribution has a 
tion most favourable for germination of the parasite, which is 
found in abundance along the margins of hills and the rims of 
_ E. Heinricher, in Centralbl. f. Bakteriobiologie, vol. xlii- 
-p. 705, 1915, states that the seeds of Arceuthobium will only 
germinate under the following conditions: presence of a living 
