illustrated by the South African Flora. 25 
quite closely related to Selago (the calyx has 3 lobes instead of 5 lobes). 
It has 31 species in South Africa, one of which extends into tropical Africa,. 
4 in tropical Africa, and 1 in Madagascar. It has a similar distribution in 
South Africa to Selago , but on the whole rather more eastern. The two 
genera, being so nearly related, obviously may be regarded as the result of 
divergence from a common ancestral type, like so many nearly related 
species already dealt with. The genus Hebenstreitia is more distinct. Of 
the thirty species, most of the annuals are central or western, i. e. in the 
drier parts, while the perennials are widespread or eastern. One species 
extends as far as Abyssinia. All the species of Dischisma (11), Micro- 
codon (5), Agathelpis (3), and Gosela (1) are endemic in the west or south- 
west. 
Lastly, as regards the species, a few examples will suffice. Heben- 
streitia fruticosa , H. den tat a, and H. integrifolia , all three of which are 
very variable and come close together, occur all over South Africa. 
H. Watsoni, on the other hand, is only recorded for East London, and 
only differs from H. integrifolia in its more lanceolate and acuminate 
bracts. H. Rehmanni (Transvaal high-veld only), again, differs in its small 
flowers and very spreading bracts. Selago supplies numerous examples of 
the same kind. 
The process of differentiation from the Scrophulariaceae, which we 
have just followed through the Selagineae (or Selaginaceae), might also 
be followed through the Myoporaceae, which Baillon (‘ Hist. PI./ ix. 420) 
again reduces to a tribe of the Scrophulariaceae. The genus Oftia has two 
species, both endemic in the western and south-western regions of South 
Africa. There are 6 genera in the family and about 80* species, mostly 
Australian, with a few Polynesian representatives; 1 in the Sandwich 
Islands, 1 in Mauritius, 2 in China and Japan, 1 in the West Indies, 1 some- 
what doubtful in tropical Africa, and 2 in .South Africa. 
Interesting points might also be brought to light by a comparison of 
the Scrophulariaceae and Bignoniaceae ; in fact, the whole of the Tubiflorae 
affords an excellent field for the study of differentiation and distribution. 
Verbenaceae. 
This family is chiefly tropical in both hemispheres. In South Africa 
the primitive tribe Stilbeae, which has endospermic seeds and in three of the 
five genera regular corollas, is entirely endemic in the south-west. In 
the tribe V f erbeneae, on the other hand, which has exendospermic seeds and 
zygomorphic corollas, one genus, Bouchea, which extends through tropical 
Africa, America, and India, is widespread over South Africa, and the others 
are all eastern. The tribe Viticeae, which differs in having the ovule 
inserted laterally instead of being basal erect, has two genera, Vitex and 
Clerodendron , each with nine or ten species, mostly rare Natal and Transvaal 
endemics except Clerodendron glabrum , which extends from Grahamstown 
