48 



PULMONARY ARTERIES Sect. IV. III. 2, 3, 4 



than thofe cii the rifing fliem, as in geum, averns ; in fcnecio aureus, 

 and the campanula rotundifoUa, fo named from the round form of the 

 root-leaf, which is alfo much broader than thofe on the ftem, as well 

 as undivided. The root -leaves of many biennial, and of fome annual 

 plants, are likewife larger, as well as of a different form from thofe 

 on the rifing flower- ftem, as in turneps and carrots. And laftly, the 

 root-leaves of fome plants, which rife immediately from feeds, con- 

 fiH: of the cotyledons of the feed, and are thus different from the 

 leaves above them. 



2. In refpe<5t to the root-leaves of palmated rhubarb and of tulips, 

 when thefe plants are raifed immediately from feed, as thefe firft 

 plants are 



k 



• 



not defigned to generate flowers and confeq 



(ced 



s 



but to produce Amply another' plant like a leaf-bud of a tree, lefs 

 oxygenation feems to have been neccflary, and the leaves therefore 



1 refpedt 



quire lefs furface, and are 

 the root-leaves of geum, 



fequence undivided 



I 



d of campanula 



difolia, which 



1- 



are larger than their ftem-leaves, it is probable that they lay up 



fervoir of 

 jps and ca 



matter for the rifine ftem, like thofe of 



o 



d thus require greater oxy 



d 



■fequence a greater furfac 



3. Another difference of root-leaves from thofe of the flem in annual 



plants often confifls in the latter being properly bra6t 



floral 



hich will be fpoken of below, while the root-leaf refembles 



thofe belonging to the leaf-buds of 



Thus in the riling ftem 



of wheat the root-leaf produces the firfl joint above the foil, and thi 

 fecond and third leaf produce joint above joint, which are each a fe 

 parate bud rifing on that below it, as is feen by the divifion of th 

 pith or hollow part of one joint from another, and at length the up 

 i)ermofl: leaf is a brade or floral-leaf belonging to the ear. 



4 



And laflly, the feed-leaves which rife out of the ground with 



the firfl joint of the flower-ftem 



kidney-bean, phafeol 



they conM of the placental artery, which was fpread on the cotyl 



dons 



b 



