316 PLANTS OF THE COAST REGION. ch. xii. 



natural home. This plant has inherited from a remote 

 ancestor a habit which is now of no service to it. The 

 young branches near the root twine round any adjacent 

 support ; but as they grow older they become stiff and 

 straight, and the taller specimens derive no adventitious 

 support from this source. 



The history of Periploca grceca, the only species 

 known to the older botanists, is somewhat different. It is 

 rather common in Greorgia, and in parts of Persia and Asia 

 Minor. Less common in Grreece, it becomes extremely rare 

 to the west of that limit, being found only in Montenegro, 

 at one place in Dalmatia, at another in South-eastern Italy 

 near Otranto, and, finally, in the pine-woods on the Tuscan 

 coast near Pisa. These facts indicate the former wider 

 extension of the species towards the west, and its gradual 

 retreat towards its primitive home in Asia. But we have 

 more direct evidence to that effect. The prints of leaves 

 unmistakably belonging to this species are not uncommon 

 in the quaternary deposits of the valley of the Arno. It 

 may probably have flourished in thickets on the Monte 

 Pisano, and on the Monte Nero near Leghorn, when these 

 were islands in a tertiary sea, and gradually descended 

 towards the Mediterranean as the coast line was advanced 

 by a change of level, and by the formation of the deltas 

 of the Arno and the Serchio. 



Another conspicuous plant, now seen for the first 

 time, was Odontospermum odorum {Asteriscus of De 

 CandoUe), forming a dense dwarf bush, about two feet 

 high. The whole plant gives out an agreeable scent ; but, 

 except in this respect, and in having the leaves covered 

 with white silky hairs, it differs very little from 0. grave- 

 olens, a characteristic species of the desert region, 

 remarkable for its offensive smell. The sweet-smelling 

 species had been hitherto found only in the Mogador dis- 

 trict, and in the Canary Islands ; but it was afterwards 

 gathered by us near Saffi. 



We reached our destination at about 5.30 p.m., and 



