66 



C1KCUMNUTATION OF SEEDLINGS. CHAP. I 



A filament was next fixed to a cotyledon only i of an inch in 

 height, which was illuminated exclusively from above, and aa 

 it was kept in a warm greenhouse, it grew rapidly ; and now 

 there could be no doubt about its circumnutation, for it described 

 a figure of 8 as well as two small ellipses in 62 hours. 



Nephrodium molle (Filices). A seedling fern of this species 



Fig. 53. 



came up by chance in a flower- 

 pot near its parent. The frond, 

 as yet only slightly lobed, was 

 only '16 of an inch in length and 

 *2 in breadth, and was supported 

 on a rachis as fine as a hair 

 and '23 of an inch in height. A 

 very thin glass filament, which 

 projected for a length of -36 of 

 an inch, was fixed to the end of 

 the frond. The movement was 

 ffephrodium molle: circumnuUtion SQ M w magnified that the 



faSs y r\Van?a^ figure (Fig. 53) cannot be fully 



from 9 A M. to 9. P.M. Oct. 30th. trusted ; but the frond was 



Movement of bead magnified 48 constantly moving in a complex 



manner, and the bead greatly 



changed its course eighteen times in the 12 hours of observation. 

 Within half an hour it often returned in a line almost parallel 

 to its former course. The greatest amount of movement occurred 

 between 4 and 6 P.M. The circumnuta- 

 tion of this plant is interesting, because 

 the species in the genus Lygodium are 

 well known to circumnutate conspicuously 

 and to twine round any neighbouring 

 object. 



Sclaginella Kraussii (?) : Selayinella Kraussii (?) (Lycopodiaceae). 

 circumnutation of A very young plant, only *4 of an inch 

 young plant, kept in j n height, had sprung up in a pot in the 

 KSTS toW PA ^-bouse. An extremely fine glass fila- 

 Oct. 31st. ' ment was fixed to the end of the frond- 



like stem, and the movement of the bead 

 traced on a horizontal glass. It changed its course several 

 times, as shown in Fig. 54, whilst observed during 13 h. 15 m.,. 

 and returned at night to a point not far distant from that 

 whence it had started in the morning. There can be no doubt 

 that this little plant circumnutatedL 



Fig. 54. 



