538 Eng lev. — Plants of the Northern Temperate Zone in their 
combined with erect habit, freer branching, and more scanty pubescence of 
the leaves, are to be seen on a plant collected first by Volkens on the 
Kilimanjaro, afterwards above Sakare, Western Usambara, by myself, and 
in Coromma Valley, Galla Country, by Riva on Ruspoli’s expedition. 
Being unable to acknowledge the specific rank of V. chamaedryoides , Bory 
et Chaub., I had named this plant V. chamaedryoides , Engl, (in Pflanzenwelt 
Ostafrikas, C, 358). Still, in order to avoid any possible confusion, I would 
rather drop this name now and substitute afrochamaedrys , Engl., in its 
place. We do not know any species in Tropical Africa which could 
possibly be compared with it or considered to be its ancestor. For 
Veronica abyssinica, Fresen., a frequent herb in the woods of Abyssinia, 
Gallaland, East Africa, and Cameroon, belongs to another affinity (that 
of the Europaeo-mediterranean V. Montana, L.). The flat seeds of 
V. afrochamaedrys , being still somewhat smaller than the 1 mm. long seeds 
of V. chamaedrys , may easily be carried away on the feet of birds. There- 
fore it is no bold speculation to assume that V ’. chamaedrys from the 
Mediterranean transported to Gallaland (probably to Abyssinia before that 
time) developed itself to V. afrochamaedrys. On this occasion, V. filiformis 
may be mentioned, which occurs in Abyssinia Highland, in America, 
and the Caucasus Mountains, and also V. violifolia , Hochst., allied to 
V. agrestis , L. 
Further, I should like to bring forward the interesting fact, reported 
by me in Sitzber. k. Preuss. Akad. Wiss., February 18, 1904, that the well- 
known Populus euphratica , Olivier, of the Mediterranean region (in the 
broadest sense) has nearly reached the equator (at Korokoro, Upper Tane 
River), and has produced there a peculiar large-fruited form named by me 
sub-sp. Denhardtiorum (in Notizbl. k. Bot. Gart. Berlin, II (1898), 218). 
Populus euphratica , Olivier, is distributed from Songaria to Palestine 
and to Western Tibet ; further, it is found on the Morocco-Algerian border, 
and has been recorded from the Libyan Desert by Ascherson, 1877. It is 
likely to be found also in Arabia on further investigation in that country. 
But at any rate there remains a wide gap of about twenty-two to twenty- 
three degrees of latitude from there to the African stations of P. euphratica . 
The African sub-species approaches somewhat the Indian specimens in 
having a long petiole and ovate remotely sinuate leaves ; it differs, however, 
most decidedly in having short (not more than 3 cm. long) fruiting- spikes 
and capsules nearly 1 cm. long, 6-7 mm. thick. It is another instance 
of a species having been modified by advancing from the temperate zone to 
its new situation. The wider expansion of the steppes in Africa being the 
result of more modern geological changes, it is safe to assume that sub-sp. 
Denhardtiorum is a younger type than P. euphratica of the northern 
temperate zone. 
In conclusion, I should like to add to the above-mentioned cases 
