456 Messrs Gardiner and Hill, The Histology 



the middle lamella as at y, until only a few islands z of 

 the original wall remain. The parts of the wall under- 

 going solution become swollen. They are indicated by 

 shading. Cell contents R. are seen in some cells. Mag. 

 460. 



Fig. 9. A cell wall from the peripheral part of the endosperm of a 

 seed in an advanced stage of germination. The ferment 

 here attacks the younger layers of the cell wall and 

 gradually works inwards. Mag. 460. 



Fig. 10. As fig. 9. The action of the ferment along the course of 

 separate threads is more clearly seen. Mag. 750. 



Figures 11 — 20, Galium Tricorne. 



Fig. 11. A young seedling with the cotyledons still embedded in the 

 endosperm. The seed has been cut in half to shew its 

 hollow nature and the position of the cotyledons (a). 



Fig. 12. A transverse section of the endosperm of a recently ger- 

 minated seed. The section has been treated with safranin, 

 which stains the unaltered cell walls (w.) but leaves 

 unstained the walls (m.) of the cells surrounding the 

 cotyledonary cleft (c.c), which have been altered by 

 ferment action. 



Fig. 13. A section of the endosperm of a germinated seed, shewing 

 the centripetal action of the ferment on the cell walls. 

 The attacked portions of the wall are shaded. T. testa. 

 The ferment appears to attack the walls with but little 

 relation to the numerous 'connecting threads' (ct.) for it 

 does not usually work along the threads, but the cell wall 

 in process of dissolution shews a crenulated edge where 

 the ferment action is taking place. Mag. 350. 



Fig. 14. A section of the endosperm of a seed in an advanced stage of 

 germination, stained with Congo red to shew the effect of 

 the ferment action on the composition of the cell wall. 

 The dye stains the attacked portions of the wall (m.) 

 (shaded in the figure) and leaves the original wall (w.) 

 unstained. The centripetal action of the ferment and its 

 method of attacking the cell wall are well seen. s. a piece 

 of a wall in surface view. T. testa. Mag. 180. 



