84 



OPHIOGLOSSACEAE 



[CH. 



Fig. 385 a, b, c. Embryos of Helminthostachys. a, shows a young state; 

 b, is more advanced; c, is still older with upright axis, and shown 

 natural size, while a, b are enlarged. /=foot, R, r, and r2 = roots, 

 ^/ = stem, r^/= cotyledon, /zj'/ = hypocotyl, s, jg^suspensor. (After 

 Lang.) 



^_^ ^ |.|p, 



Fig. 386. Opliioglossum viilgatzivi. The central figure shows an archegonium at the period of 

 fertilisation. The left-hand figure shows the first division of the zygote. To the right a more 

 advanced embryo. /, /, the basal wall; ep, epibasal ; hy, hypobasal hemispheres;/, the 

 region of the foot; w, root ( x 225). (After Bruchmann.) 



Bruchmann states, however, for O. vulgahnn that the hypobasal half gives 

 rise to the first root and foot : the latter is never large, but only appears as 

 a slight swelling. The root rushes forward forming its apical cell early 

 {w, Fig. 387), It bursts freely through the prothallus before there is yet any 

 definite trace of the axis or cotyledon (Figs. 379, 387). Up to this time the 

 embryo is stored with nutritive substances, but there is no endophytic fungus, 

 and the development of O. vulgatiun up to this stage may occupy several 

 vegetative seasons. The differentiation of the long-delayed shoot is accom- 



