414 



BOTANY 



rows of cells constituting the neck are more elongated and, on opening, 



Tmml 



Fig. 347. — Equisetum arvense. 1. Fertile haulms terminating in the flower-cones (a) ; 2, a sterile 

 vegetative haulm ; a, rhizome tubers ; 3, sporophyll with sporangia ; 4, sporophyll with 

 ruptured sporangia ; 5, 6, 7, spores with the spiral hands of the perinium. (After Wossidlo.) 



curve strongly outwards. The development of the embryo corresponds, 



