air THE COROLLAS or rL0\TER3. 



179 



by measurement : whereas eraporation is air and waterijiixed, 

 issuing from pores so very diminutive, that no eye, even 

 aided by the.^olar microscope, can see tliem. It can nei- 

 ther ie accrelerated, nor retarded ; nor can it be ascertained, 

 ^since*tt4isaij pears as fast as it is collected for the purpose). 

 1 before showed what the watery cryptogamiae were, by Watery cryo- 

 drawings of many plants of the sort; nourished by the togamiat al- 

 d'ews of the atmosphere ; and 1 think it will be granted me, ^J^ ^jj" 

 that perspiration could not have stalks, whicb most of 

 these watery bubbles have. It is curious they should 

 always turn milk-white. 



Flowers in hot climates (at least most of them) are thick Adaptation of 



in the petal, probably to <juard the muscles from heat. To P'^"^^ ^^ ^^e 



i)1hc6s where 

 trace the effect of heat and cold in plants, to trace different they are to 



climates in their productions, is the most delightful study ;8^'^^* 

 and one congenial to this, my present employment. Who 

 can dissect the betula, and not be assured it is formed to 

 endure the extremities of cold ? Formed of 14 or l6 sepa- 

 rate rinds (not barks) something like the skin I have before 

 described, with a powder between each, how could frost 

 approach it ? Who can dissect the water lily with its large 

 ftnd prpminent air vessels fluted, and with vacuities ma- ' 

 naged like the fish either to raise it in water or depress it, 

 and not be sure it is formed to live in that element? Who 

 can dissect the boletus, formed like a sponge, and guarded 

 in its interior, without seeing it is to grow in caverns and 

 underground ? or the ^x/r^me alpine plants, with their watery 

 and open vessels, that they want little more than the dews 

 of the atmosphere, and are not to depend on their rocky 

 heights for food? But it is impossible long to dissect 

 plants, and not see there are certain marks and indications, 

 that give proof of all this, 



I am, Sir, 



Your obliged servant, 

 AGNES IBBETSON. 



Eji-planalion of the Piatis, 

 Plate V. figs. 3, 4.— Rose pejtal : %, 3, Ppiper skip, 

 pink; fig. 4, pabulum, wl»ite. 



XV -3 Fieri. ^, 



