516 MODIFIED CIRCUMNUTATION. Chap. X. 



which was already curved 36° beneath the horizon, was observed 



from 11 A.M. July 22nd to the 27th, by which latter date it 



had become vertically dependent. Its course during the first 



12 h. is shown in Fig. 190, and its position on the three 



.succeeding mornings until the 2oth, 



Fig. 191. when it was nearly vertical. During 



the first day the peduncle clearly 



circumnutated, for it moved 4 times 



down and 3 times up; and on each 



succeeding day, as it sank downwards, 



the same movement continued, but 



was only occasionally observed and 



was less strongly marked. It should 



TrifoliumMerraneum: cir- "^^ stated that these peduncles were 



cumnutating movement of observed under a double skylight in 



peduncle, whilst the flower- the house, and that they generally 



head was burying itself in ^^^^^ downwards very much more 



sand, with the renexed tips •' 



of the calyx still visible ; slowly than those on plants growing 

 traced from 8 A.M. July out of doors or in the greenhouse. 

 26th to 9 A.M. on 27 th. The movement of another vertically 

 Gla=;s filament nxed trans- , j x j i -ii ii ji 



versely across peduncle, dependent peduncle with the fiower- 

 ■iiear flower- head. head standing half an inch above the 



ground, was traced, and again when 

 it first touched the ground; in both cases irregular ellipses 

 were described every 4 or 5 h. A peduncle on a plant which 

 had been brought into the house, 

 ^'S- 192. moved from an upright into a ver- 



tically dependent position in a 

 single day; and here the course 

 during the first 12 h. was nearly 

 straight, but with a few well-mark* d 

 rrifo'iun subterraneum ; move- zigzags which betrayed the essential 

 ment of same peduncle, with nature of the movement. Lastly, 

 flower-head completely buried the circumniitation of a peduncle 



beneath the sand; traced from „ . j j . ,-■, , , ., , . 



8 a.m. to 7. 15 P.M. on July 29th. ^^^ ^^^'^^^ '^"""g 51 h. whilst ID 



the act of burying itself obliquely 

 in a little heap of sand. After it had buried itself to such a 

 depth that the tips of the sepals were alone visible, the above 

 figure (Fig. 191) was traced during 25 h. When the flower- 

 head had completely disappeared beneath the sand, another 

 tracing was made during Hh. 45 m. (Fig. 192); and here again 

 we see that the peduncle' was circumnutating. 



