Mr. Beown, on the Profeacea of Jussku. 23 



Genera consistino; of one or very few species, and which ex- 

 hibit generally the most remarkable deviations from the usual 

 structure of the order, are the most local, and are found either 

 in the principal parallel, or in the highest latitude. 



The i-ange of species in the whole of the order seems to be 

 very limited ; and the few cases which may be considered as ex- 

 ceptions to this, occur in the most extensive genera, and in such 

 of their species as are most strictly natives of the shores. Thus 

 Banksia integrifolia, which grows more within the influence of 

 the sea than any plant of the order, is probably also the most 

 widely extended, at least in one direction, being found within 

 the tropic, and in as high a latitude as 40". It is remarkable, 

 however, that with so considerable a range in latitude, its ex- 

 tension in longitude is comparatively small : and it is still more 

 worthy of notice, that no species of this family has been found 

 common to the eastern and western shores of New Holland. 



The celebrated traveller Humboldt is the first who has ex- 

 pressly pointed out a remarkable diflference in the distribution of 

 the species of plants. 



He observes that, while the greater number grow irregularly 

 scattered and mixed with each other, there are some which form 

 considerable masses, or even extensive tracts, to the nearly ab- 

 solute exclusion of other species. Of plants growing thus in 

 society, the greater number occur in the temperate zones ; and 

 of these, the most decided instances will readily present them- 

 selves to every botanist. I venture to add, that such as exist 

 within the tropic, are found, either at considerable heights or 

 on the sea-shores. 



To this class very ftw of the Proteaceee can be said to belong. 

 Protea argenfea of Linnaeus is the most striking example among 



the 



