BOTRYCHIUM VIRGINIANUM. 

 RATTLE-SNAKE GRAPE-FERN. 



NATURAL ORDER, FILICES. 



BoTRYcmUM ViRGIMANUM, Swavtz.— Somewhat hairy. Sterile division of the frond about the 

 middle of the stipe, ternately divided to the base, sessile, the divisions four to six inches 

 long, broad-ovate, or somewhat deltoid in their outline, bipinnatifid, green; pinnse one to 

 two inches long, deeply pinnatifid, the lobes cuneate-oblong, incisely dentate at the apex. 

 Fertile portion on an erect stipe nine to eighteen inches high, in a reddish-tawny compound 

 spike two to five inches in length. (Darlington's Flo7-a Ccstrica. See also Gray's Manual 

 of the Botany of the A'orthern United States, Chapman's Flora of the Southern United 

 States, Wood's Class- Book of Botany, Eaton's Ferns of North America, and Williamson's 

 Ferns of Kentucky.^ 



HE leading description has been taken from Darlington's 

 " Flora Cestrica," chiefly because the drawing is from a 

 Pennsylvania specimen, and further because it may serve to illus- 

 trate how far the knowledge of the origin of the various parts of 

 a plant's structure has progressed since Dr. Darlington's time. 

 The work from which we quote was published in 1S53, and at 

 that time it was by no means widely known that every part ot a 

 plant's structure was formed in its earliest stages out of what 

 might be leaves. This knowledge, however, has to be wholly in- 

 ferred from results ; for the most powerful microscope has failed 

 to discover this early individual leaf-form in any particular plant, 

 before it takes on the peculiarities by which we are able to dis- 

 tinguish one part from another. At the time of which we write 

 this science, known as Morphology, was comparatively new, and 

 Dr. Darlington, as we may judge from some of his writings at 

 that time, was a believer in its doctrines ; but we can see by the 

 way the description is written, though it accurately describes our 

 plant, he did not understand the full import of morphology in de- 



(•45) 



