302 MR. J. BALL’S SPICILEGIUM FLORH MAROCOANS. 
Southern Spain, Greece, and Asia Minor. On the arenaceous and 
porphyritic rocks of the Ait Mesan valley we found to a great ex- 
tent the same endemic species afterwards gathered on the schistose 
and caleareous rocks of Djebel Tezah, at least 30 miles distant. 
Another fact worth noticing is, that, among a considerable num- 
ber of new specific forms, no new generic type has yet been found 
in the Great Atlas. 
But in my opinion the most singular point about the Great- 
Atlas flora is the presence of a large number of the common 
species of Central Europe, both annual and perennial, coupled 
with the fact that many of these are not species that have proved 
their power of adapting themselves to different climatal condi- 
tions, and that many of them have no nearer habitat than the 
mountains of Central or Southern Spain, while others must be 
sought at a still greater distance. 
The conclusion to which I am led by a consideration of the facts 
is the same that I have derived from rather long observation of 
the mountain-vegetation of Central and Southern Europe—namely, 
that it is impossible to explain the facts without admitting that 
a large portion of our present flora is relatively very ancient, 
and that the species had assumed their present characters at least 
as early as the Miocene epoch. 
I ought not to omit mentioning that two years after our visit 
two German naturalists, MM. Rein and Fritsch, were able to 
make a short expedition in the Great Atlas, nearly following our 
footsteps. They were not exclusively engaged in collecting plants ; 
but they have deposited at Kew specimens of most, if not all, the 
plants found by them. Having been able to examine these, I 
have enumerated their specimens in the following catalogue. 
In determining the specimens of our collections I have been 
materially assisted, in regard to the Orchidex, by my friend Prof. 
H. G. Reichenbach. The friendly aid and assistance of Professor 
Oliver and Mr. J. G. Baker have been frequently invoked by me ; 
and to the latter I am especially indebted for his thorough know- 
ledge of the Liliacee and Amaryllidee of the Mediterranean 
region, which he kindly contributed for my benefit. To Mr. 
Bentham, it is needless to say that in any case of doubt or diffi- 
culty I never applied in vain. The resources of his unequalled 
knowledge are always at the service of the younger and less-gifted 
workers in the field of science ; and I cannot better close than by 
expressing the sense of affectionate regard with which I acknow- 
ledge his guidance. 
