CHAP. IV. CIKCUMNUTATION OF CRYPTOGAMS. 257 



small space, but during the night and the whole following day 

 it ascended in the same general direction; the ascent being 

 effected by repeated up and down well-pronounced oscillations. 



CKYPTOGAMS. 



(34.) Nephrodium molle (Filices, Fam. 1). A filament was 

 fixed near the apex of a young frond of this Fern, 17 inches 

 in height, which was not as yet fully uncurled ; and its move- 

 ments were traced during 24 h. We see in Fig. 119 that it 



Fig. 119. 



Nephrodium mollc : circumnutation of rachis, traced from 9.15 A.M. May 

 28th to 9 A.M. 29th. Figure hero given two-thirds of original scale. 



plainly circumnutated. The movement was not greatly magnified 

 as the frond was placed near to the vertical glass, and would 

 probably have been greater and more rapid had the day been 

 warmer. For the plant was brought out of a warm greenhouse 

 and observed under a skylight, where the temperature was 

 between 15 and 16 C. We have seen in Chap. I. that a frond of 

 this Fern, as yet only slightly lobed and with a rachis only *23 

 inch in height, plainly circumnutated.* 



* Mr. Loomi-s and Prof, Asa 

 Gray have described (' Botanical 

 Gazette,' 1880, pp. 27, 43), an 

 extremely curious case of more- 

 ment in the fronds, but only in 

 the fruiting fronds, of Asplenium 

 trichomanes. They move almost 

 as rapidly as the little leaflets 



of Desnmdium gyrans, alternately 

 backwards and forwards through 

 from 20 1o 40 degrees, in a plane at 

 right angles to that of the frond. 

 The apex of the frond describes " a 

 long and very narrow ellipse," so 

 that it circumnutates. But the 

 movement differs from ordinary 



