CHAP. II. CIRCUMNUTATION OF HYPOCOTYLS, ETC. 107 



his knees and still wriggling ; and this may represent 

 the bowing backwards of the basal leg of the arch, 

 which in most cases aids in the withdrawal of the 

 cotyledons from the buried and ruptured seed-coats, 

 and the subsequent straightening of the whole hypo- 

 cotyl or epicotyl circumnutation still continuing. 



Circumnutation of Hypocotyls and Epicotyls, when 

 erect. The hypocotyls, epicotyls, and first shoots of the 

 many seedlings observed by us, after they had become 

 straight and erect, circumnutated continuously. The 

 diversified figures described by them, often during two 

 successive days, have been shown in the woodcuts in 

 the last chapter. It should be recollected that the 

 dots were joined by straight lines, so that the figures 

 are angular ; but if the observations had been made 

 every few minutes the lines would have been more 

 or less curvilinear, and irregular ellipses or ovals, or 

 perhaps occasionally circles, would have been formed. 

 The direction of the longer axes of the ellipses made 

 during the same day or on successive days generally 

 changed completely, so as to stand at right angles to 

 one another. The number of irregular ellipses or 

 circles made within a given time differs much with 

 different species. Thus with Brassica oleracea, Cerintlie 

 major, and Cucurbita ovifera about four such figures 

 were completed in 12 h. ; whereas with Solanum palina- 

 canihum arid Opuntia basilaris, scarcely more than one. 

 The figures likewise differ greatly in size ; thus they 

 were very small and in some degree doubtful in Stapelia, 

 and large in Brassica, &c. The ellipses described by 

 Lathyrus nissolia and Brassica were narrow, whilst 

 those made by the Oak were broad. The figures are 

 often complicated by small loops and zigzag lines. 



As most seedling plants before the development 

 of true leaves are of low, sometimes very low stature, 



