4 



w. H. PEAESON. 



[No. 3. 



and I call the upper face of a stem or branch, antical; the 

 under or rooting face, postical; and the sides, right and left of 

 the axis, lateral. 



In estimating the comparative dimensions of leaf-cells I 

 have used the scale proposed in my paper on Anomoclada ( Journ. 

 Bot. 1876) which I here subjoin for reference. 



The comparative size of the cells of Hepaticae: 

 Cellulae diametro 

 magnae (large) Vio mni = .10 mm. 



majusculae (rather large) V20 nim = .05 mm. 



mediocres (medium size) V30 mm = .033 mm. 



parvulae (smallish) V40 mni = .025 mm. 



parvae (small) Vso mm = .02 mm. 



minutulae (very small) Veo mm = .0167 mm. 



minutae (minute) V^o mm = .0143 mm. 



minutissimae (very minute) Vso — Vioo mm = .0125 — .01 mm." 

 I have also used the terms employed by Dr. Spruce in his 

 „Hepaticae Amazonicae et Andinae" in describing the comparative 

 size of Hepaticae. 



Elata 4 to 6 inches. 



Majuscula , 

 Elatiuscula 

 Mediocris . 

 Pusilla . . 

 Minuta . . 

 ,It is difficult to 



. about 3 inches. 

 . about 2 inches. 

 about an inch to inch and half. 

 from V4 to % inch. 

 . 2 mm to 4 mm. 

 propose any general scale of sizes for all 

 Hepaticae. What is small for a Bazzania may be large 

 for a Cephalozia etc.| In my book I have spoken of Frulla- 

 nia atrata growing to half — a — yard loug — in reality 

 the sterile stems were often fuUy a yard — some of my fertile 

 specimens are 21 inches long." 



K. S. 



