MOVKMKNTS OF LKAVKS. 



98 



Tn vcrnutioii (wliilc tlif lent' i.< very 

 youn;^ in tlio hud) the It jivcs tuki' tho 

 Hiimo [toHitionrt as when full <fr»nvii and 

 (Irii'il, tli<ni;;li the hullifonn cells at tliat 

 tiinc, an* V(M'y small, as we should cx- 

 ])()('t. Tlu* very youujLj leaves of /htt/iflis 

 i/I(uiifni/(t (orchard ^M'ass) and /'nti /nuifni- 

 sis (Juno <;rass) are contluplieate, wliilo 

 thoso of I*lih'iiiii /y/v^/r//,s7' v'i'iniotliy), aro 

 convoluti!. Soino youi\j^ leaves (unnhino 

 thoso two modes morn or h'ss, and nuiy 



Fi(!. ntl. A «Ti)ss BPcMon of 



bo (!ondui)ll('ato in the niiddlo and coji- yl>nn^i\^:^^n^f Aim vaotitnimt, 



' ^lidwinu Its miido <>l vci'imtion 



volute on the nuiru'ins. within thonluatl.. I «:t.'. 



The Movements of the leaves of some Lejruniinos.e at'e vei-y 

 quick, in most grussi-s they are (|uite slow, dependinj^ ou the light 

 and chiingo of moisture. In the hlades of jrniss the motion when 

 drying, consists in the ai)proach «)f Hk; siiles Avheii (■ondu])]ieiito, 

 or in rolling or unrolling when convolute, and in torsion Avlieii 

 turning tin- lower surface to tin* sun. 



In isr»8, Mr. Duval -J«»uvo was snrj)rise(l to see tlie heaves of 

 Lcerxia ori/zoif/r.s (rico cut-grass), move quito cjuickly, its he 

 brushed them. The motion begins tit the apex and extends down 

 to tho base, iind is convolute when closed. Other species of this 

 genus behave in like manner, as also (b)es Scyh'/'itt r/rridfa. 



A drop of water on the section of the leaf of the hitter causes 

 it to expiintl instantly. The stime is true of ti leaf of Poa 

 pratensis or of Dacfijlis. Some leaves ojxmi very slowly tind then 

 only when quite moist, as in case of Ljuiouni K/iurfcum, or Xanhm 

 atricta. 



Tho annnal species of AirttinuX Cl/a/naf/rosfis ?m/w/w?^/ iiro abso- 

 lutely destitute of motion. 



Many remain rolled up when dry, jind unroll at night when 



