436 



which ocxurred almost exchisively in roots of the second order: 

 Ran. sulphureus^ acer\ affinis, nivalis and pygmœus. Hesselman, 

 in his paper "Om Mykorhizabildningar in ark. Växter" (Bih. 

 Kg]. Sv. V^et. Akad. Handl. Bd. 26, Afd. Ill), mentions no Ranun- 

 culaceæ. — Root- h airs were found in R. glacialis. 



B. The roots of Anemone Richardsoni and of Coptis tri- 

 folia are very similar. The epidermis is strong ; the exodermis 

 is not very prominent and the cell-walls of it and of the rest 

 of the cortex are fairly thick ; the intercellular spaces are very 

 small; no broken-down parts were observed. The endodermis 

 has somewhat thickened walls which were found to be suberized. 

 The central cylinder of Anemone Richardsoni was found to consist 

 altogether of primary elements; in Coptis trifolia some secon- 

 dary wood is developed; from two to three radial masses of 

 wood occur. In both species spongy hyphae occurred in 

 roots of the second order. — Roots- h airs were found in 

 Coptis trifolia. 



С The roots of the first order in Thalictrum alp. have 

 vigorous secondary growth in thickness; the primary cortex is 

 thrown off. The outermost layers both in the latter and in the 

 secondary cortex have collenchymatously thickened walls. The 

 primary radial masses of wood number from three to six. The 

 secondary roots are of primary structure and are peculiar owing 

 to the presence of a dimorphic epidermis; they were found to 

 contain spongy hyphae. 



VI. The vertical rhizome in the species oi Ranunculus 

 of the PrmM/a-type is very similar in structure in the different 

 species ; usually it is schizostelous. In regard to R. acer, a 

 smaller amount of lignified elements was observed in the spe- 

 cimens from the northern localities than in those investigated 

 from Denmark. 



VII. The stem and the peduncle in all the species, 

 were found to be on the whole similar in structure. The 

 bundles are closed and are arranged in a ring. The strength- 



