442 Mr Berwick's Observations on 



The radicle emerges by an aperture of its own making, 

 although there is in the seed a large cavity which has no 

 connection with the exit of the radicle, or indeed of the 

 cotyledons. The radicle is in a curved position for some 

 time after protrusion. In the embryo (Plate III., fig. 10), 

 the radicle in germinating formed a loop, and in the curve 

 towards the apex of the radicle, where it touched the soil, 

 the horizontal raphides were present. But it is questionable 

 whether the curving of the radicle has any connection with 

 the laying down of the raphides in a horizontal position. 

 Possibly in the root, as well as in the rootlets, the develop- 

 ment of the root-cap may have some connection with the 

 laying down of the horizontal raphides, but if so, why are 

 the raphides vertical at the apices of both root and rootlets ? 

 In young rootlets, almost invisible to the naked eye, small 

 groups of horizontal raphides occur frequently. These are 

 carried forward in situ, the columns increasing in depth, 

 according to the length of the rootlet, the vertical raphides 

 duly appearing at the extreme apices. 



Eaphides, then, in the seedling, as in the adult plant, 

 usually occur abundantly in all parts of the plant in the 

 vertical position, except as indicated in the region of the 

 root-caps of the root and of the rootlets. 



It is stated by De Bary that cells correspond in shape to 

 the groups of crystals they contain.* I find this to be the 

 case in those of the plant under consideration. It may 

 here be noted that in adult leaves the bundles often seem 

 to have outgrown their cells. 



A single group of raphides occurred in several adult 

 cotyledonary glands (Plate III., fig. 4, r.). It was found some- 

 times in the stalk, and sometimes in the centre of the gland, 

 and it lay beneath the outer layer of cells. 



In the crystals before us I have not detected the mucilage 

 referred to by De Baryt and Strassburger, | as occurring 

 around certain plant crystals, although I have observed 

 granular contents in cells of the rootlets containing raphides. 



Some seeds of Galium Aparine, from which the seed 

 coats were removed, were sown in soil previously treated 



* De Bary, Comp. Anat., Eng. trans., 1884, p. 138. 



+ Ibid, p. 139. 



J Strassburger, Practical Botany, Eng. trans., 1887, p. 98. 



