EMBRYOLOGY 
Fic. 214. 
Embryo of Zguisetum. 1.-IV., Eguisetum arvense, L. I. and II1., the same embryo 
in different positions : in I. the median wall is visible, in II. the transverse wall. x 300. 
III.-IV., a more advanced embryo showing development of the stem and leaf-sheath. 
X250. V., an embryo still further developed, but not dissected free from the prothallus, 
and showing the orientation relatively to the archegonium. s¢=the stem apex ; v=the 
first leaf-sheath ; w=the root. X98. WI. and VII., Aguisetum palustre, L. VI.= 
young embryo still in the archegonium, stem and foot are visible. 300. VII.=an 
embryo further advanced, and dissected free, and orientated go” as compared with VI. 
The root (w) and stem (s/) are visible. 300. 4=basal wall; 7=transverse wall ; #z= 
median wall; e=epibasal and 4=hypobasal region; w=the first leaf-sheath. (After 
Sadebeck, in Engler and Prantl, Naz. Phanzenfam.) 
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