OF THE AMENTUM! 249 



the whole scale remains, enlarges, hardens, 

 and protects the seed, as in Tinus, the Fir 

 tribe. Such is the case with catkins of 

 fertile flowers, which are necessarily per- 

 manent till the seed is ripe ; barren ones 

 fall as soon as the stamens have performed 

 their office. Every catkin consists gene- 

 rally of either one kind of flower or the 

 other. There are few certain and invari- 

 able instances of stamens and pistils in 

 the same catkin, that circumstance oc- 

 curring chiefly in a few species of Salix 



and Carex; nor is Typ'ha, t. 1455 — 7, 

 an exception to this. Examples of barren- 

 flowered catkins are seen, not only in Salix 

 and Piniis, but in several plants whose 

 fertile or fruit-bearing flowers are not cat- 

 kins, such as the Walnut, and, unless I am 

 much mistaken, the Hasel-nut, t. 723. 

 Each nut or seed of the latter has a per- 

 manent coriaceous calyx of its own, inad- 

 vertently called by Gaertner an involucntm, 

 though he considers the whole as an amen- 

 turn, which this very calyx proves it not 

 to be*. Hamulus, the Hop, t. 427, has a 

 catkin for the fertile {lower only. 

 * It appears moreover that Carpinus, the Hornbeam, 



