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Transactions of the Society. 



earth, while the arching upper part grows upwards and extricates 

 the cotyledons (fig 37.). 



In some cases, as was first pointed out by Flahault, for instance, 

 in the Cucumbers, Mimosa, and Cuphea, the withdrawal of the 

 cotyledons is facilitated by the development of a projecting lip at the 

 union of the radicle and hypocotyl ; this holds down the lower half 

 of the seed-coat, while the continued growth of the hypocotyl forces 

 up the upper half, thus enabling the cotyledons to make their exit. 



Fig. 37. — Scabiosa australis. x 6. 



The commencement of germination. In A the radicle (r) only has 



protruded ; in B the cotyledons (c) are nearly free. 



In other cases, as in the Flax, Cress, Chamomile, etc., the seeds 

 are held to the ground by a secretion of mucus or gum. 



In Scabiosa gramuntia (fig. 38) the fruit is crowned by a well 

 developed cup-like lamina, and the root on leaving the seed curves 

 over in an arch and pins the fruit to the ground, thus enabling the 

 cotyledons to draw themselves out. 



In S. graminifolia the cup-like lamina has thickened ribs, be- 

 tween which are thinv.er membranes, which the root can easily 

 pierce. 



