THE ANNALS 



AND 



MAGAZINE OF NATURAL HISTORY. 



[THIRD SERIES.] 

 No. 24. DECEMBER 1859. 



XL. — On the Forms and Structure of Fern-stems. By George 

 Ogilvie, M.D., Lecturer on the Institutes of Medicine in 

 Marischal College and University, Aberdeen*. 



[With three Plates.] 



On the Vegetative Axis of Ferns. — For the following observa- 

 tions the author makes no further claim to originality than that 

 they were suggested to him by researches which he was led to 

 undertake from finding the subject scarcely noticed at all in our 

 common botanical works. 



External Characters of Fern-stems. 



By the corm or vegetative axis of Ferns, it is hardly necessary 

 to mention, is meant that part which, in our indigenous species, 

 is commonly termed the root, as being more or less buried in 

 the soil, though it does not differ essentially from the arbores- 

 cent stem of the Tree-ferns of tropical and southern latitudes. 

 Even in our British species, however, the corm or vegetative axis 

 presents considerable diversity of form. The author has to re- 

 gret that his opportunities of investigating the varieties of this 

 organ have been so limited. He has been restricted, not only 

 to our indigenous species, but, with few exceptions, to those 

 growing in his own neighbourhood ; for, though specimens of 

 fern-fronds are readily enough to be had in exchange, few col- 

 lectors preserve the rhizomes. From the examination, however, 

 of such species as he has been able to procure, he believes that 

 the corms of our British Ferns — if not of the tribe generally — 

 may be reduced to the three forms of a stoloniferous rhizome, 

 and a caudex, simple or branched. 



* Communicated by the Author, having been read before the British 

 Association, Sept. 15, 1859. 



Ann. $ Mag. N. Hist. Ser. 3. Vol. iv. 26 



