Prof. G. Gulliver on the Raphides of Rubiacece. 53 



for the most part in bundles, in the cellular tissue of young, 

 healthy, and growing parts of the plant, particularly in the leaves. 

 There are orders, especially among Monocotyledones, in which 

 the distribution of raphides is very irregular, as might have been 

 inferred from the few observations in the 'Annals' for last 

 January, p. 15. Thus, the first two orders, Trilliacese and Dios- 

 coreacese, abound in raphides, which are not found in any of our 

 plants of the next order, Hydrocharidacese, and yet appear again 

 abundantly in the succeeding order, Orchidacese. In Iridacese 

 there are long crystals, not like those in the preceding orders 

 just named, but thicker and apparently prismatic in form, and 

 occurring singly instead of in bundles. The orders immediately 

 following, namely, Amaryllidacese, Asparagacese, and Liliaceaj, 

 abound, again, in true raphides, which are generally, if not regu- 

 larly, absent from Juncacese, Potamogetonaceae, Cyperaceae, and 

 Graminese. Many instances also occur of some species abound- 

 ing in, and others devoid of, raphides, in one order, as is the case 

 in Liliacese. Hence it would appear that the existing knowledge 

 of the distribution of raphides must be vague, seeing that it is 

 stated, in our latest and best repository of the minute anatomy 

 of plants, the ' Micrographic Dictionary,' that raphides are abun- 

 dant in Monocotyledones generally. But it is proposed to treat 

 of this subject more particularly in another communication. 



The statement in the same Dictionary, that " there are few of 

 the higher plants which do not contain raphides," is entirely at 

 variance with my observations. But perhaps it may be intended 

 in that book to include any kind of crystals, even if resulting 

 from decay or decomposition of the tissues. I found no true 

 raphides in the leaves of the few species examined of such orders, 

 too numerous now to detail, but among which were Ranuncu- 

 lacese, Papaveraceae, Fumariacese, Cruciferse, Violacese, Car}o- 

 phyllacese, and Umbelliferse. Let any one, for instance, compare 

 the abundance of these raphides in the vigorous young leaf-cells 

 of Onagracese with the total absence of such raphides in the same 

 part of Lythracepe and Haloragacege, and the difference will be 

 immediately apparent. The varieties of Fuchsia and the equally 

 common Cuphea platycentra, which are plants at hand even in 

 the humblest collections, will answer this purpose, as well as our 

 native species of the two orders, and afford instructive examples 

 of the facts in question. I have lately found raphide-bearing 

 plants thus charactei'ized in the seed-leaves; so that (Enothera and 

 Epilobiuin may be distinguished from their allies of other orders, 

 by rapliides alone, even in that rudimentary state of growth ! 



Edeubridge, June 15, 1863. 



