483 X. GENERAL REMARKS. 



Fully admitting the imperfections of such a climatal 

 arrangement, it is still conceived that some interest would 

 attach to an arrangement of the whole flora into a double 

 linear series, according with the presumed mean annual 

 temperatures under which the species have their re- 

 spective limits, upper and lower, colder and warmer. The 

 data for such an arrangement all exist in the preceding 

 pages ; but the necessity of economizing space prevented 

 further repetitions of the long list of names. Such an 

 arrangement for upper limits might be founded upon that 

 for the plants of the Grampian mountains, by interposing 

 the few colder temperatures stated elsewhere, and then 

 adding to the list those other species which apparently 

 cease under higher temperatures, whether by latitude, or 

 by altitude in the list for North England. The short 

 thermal list of lower limits, on pages 352 to 356, might in 

 turn be carried out by uniting therewith the latitudinal 

 temperatures of species reaching further southward at 

 slight elevations. 



No ordinal summaries were made in accordance with 

 the temperatures ; because these were mainly inferences 

 either from latitude or from altitude. The summaries 

 or census of orders were founded on those two geographi- 

 cal conditions instead ; first, taken separately and inde- 

 pendently, by the latitudinal divisions and the stages of 

 elevation ; and then, connectedly, by the ascending or cli- 

 matal zones, in which the two former conditions were 

 supposed to compensate or balance each other. These 

 zones again fall under remark in the next section. 



11. Climatal Zones of Plants. 



The arrangement of plants into climatal (a more Eng- 

 lish-like termination than " climatic ") zones was explained 



