Glands in the Cotyledons. 439 



occurring in the leaves. I found a group of glands in the 

 axil of an adult leaf. 



Notes on Development of the Vascidar System, &c. 



In the embryo of Galium Aparinc no spiral vessels are 

 differentiated, but they soon appear on exit of the radicle, a 

 bunch being formed, which splits into two gToups, one for 

 each cotyledon. In the cotyledon (Plate III., fig. 7), one 

 vessel of each group is alternately given off" to each side, and 

 the rest form a mass whose extremities emerge in a series 

 of water pores * (Plate III., fig. 7, w. p.), just below the 

 indentation on the upper surface of the cotyledon. The 

 adult cotyledons bear the hooked hairs (Plate III., fig. 7, h.), 

 characteristic of the plant. The root, which consists of rows 

 of longitudinal cells, becoming compressed towards its apex, 

 has a greater or less development of spiral vessels, but the 

 rootlets, which are similar in structure, have usually only 

 two spiral vessels. 



"When placed in a flame the seed of Galium' Aparinc 

 detonates, ignites, and becomes red hot, after the manner of 

 the coffee bean, though on a smaller scale. I found that the 

 roasted seed could be used as a substitute for coffee. But 

 the recommendation that it might be so used has already 

 been made. It was noticed that boiling with caustic soda 

 caused in the seedlings reddening of the root, and blue 

 coloration in the stem at the base of cotyledons, while 

 caustic potash turned the same part of the stem brown and 

 the root red. The blue tint permeated the cotyledons, 

 being most marked round the margins; it also spread into 

 the primary leaves, and often into the glands. But no 

 coloration took place on boiling an embryo dissected out of a 

 seed, or on any portion of an embryo which had required to 

 be dissected out. Thus a blue coloration indicated after 

 boiling how far the radicle had protruded from the seed. 

 There was a brown and blue in a seedling where radicle had 

 projected "2 of an inch, and in that where radicle had pro- 

 jected '3 of an inch there was a patch of blue indicating the 

 point of junction with the seed. If a living seedling is 

 placed in HCl, at the bend beneath the cotyledons, a 



* See TurnbuU on " Water Pores," Annals of Botany, vol. iii., Xo. ix., p. 123. 



