Prof. G. Gulliver on Raphides and other Crystals in Plants. 457 



botanists,it must now be admitted that the British Dictyogens also 

 truly and naturally differ, in the possession of this character of 

 raphis-bearing, from their nearest neighbours of other orders. 

 And the same character has been found in every exotic species 

 of the class hitherto examined by me in this respect. 



The names of the plants thus examined have been specified in 

 preceding parts of these Observations. And since the present 

 paper was in type, Mr. W. H. Baxter, the botanist to whom I 

 have so often been indebted for generous assistance in these 

 inquiries, has sent me fragments of leaves of three Dictyogens, 

 of which notes of my examinations here follow : — Dioscorea 

 discolor : raphides swarming. Philesia buxifolia : raphides much 

 less abundant, but yet rather numerous. Roxburghia gloriosoides : 

 true raphides very scanty ; but a profusion of crystal prisms 

 lying singly between and parallel with the transverse veins of 

 the leaf. 



Aracece. — In the last communication, it should have been 

 noticed that I have found, as was expected, an abundance of 

 raphides in Pistia stratiotes ; they occur with a plentiful crop of 

 sphseraphides in this plant, and the cells of both are very distinct. 



Nyctaginacece. — Besides the plants mentioned in the 'Annals' 

 for last October, I have recently, through the courtesy of Mr. 

 W. H. Baxter, had an opportunity of examining fragments of 

 several dried specimens of this order. Of these the following 

 are notes: — Boerhaavia panicidata [leaves, twig, and flower-buds]: 

 abounding in raphides. Collignonia scandens [leaf and flower] : 

 raphides small and very scanty, with some bits of larger crystal 

 prisms. Neea obovata [leaf and flower] : many raphides and 

 larger crystal prisms. Pisonia aculeata [leaf, flower, and twig] : 

 raphides abundant in the flower and twig, and, with many crvs- 

 tal prisms besides, in the leaf. Tricycla spinosa [stalk, leaf, 

 bracts, and fruit] : raphides swarming in all these parts, and 

 some in the corolla and seed-skin. Okenia hypogcea [twig and 

 leaf] : raphides abundant. Add to these, cultivated plants of 

 Abronia, in the leaves and seed-leaves of which, as well as in the 

 persistent calyx of the fruit, I have constantly found numerous 

 raphides. 



Taking the orders Plantaginacese, Nyctaginacese, and Ama- 

 ranthacese as they stand lineally in Prof. Balfour's ' Manual of 

 Botany/ the central and exotic order differs (like three orders of 

 our native Dicotyledones; ' Annals,' July 1864), in the possession 

 of this character of raphis-bearing, from its next neighbouring 

 orders. And so, too, regarding the recognized affinity of Nycta- 

 ginacese with Chenopodiacese, the result is still similar; for, 

 although I have often shown how abundant sphseraphides are in 

 this last order, I have not seen true raphides in it ; nor have I 

 u nd Polygonacese a raphis-bearing order. 



