LINNEAN SOCIETY OF LONDON. lxix 
tion of its raphe and micropyle, considered with reference to their 
constancy or variability in large groups of plants, verifying and 
following up those which have been already published by one of our 
most careful observers, Mr. Benjamin Clarke,—on the constancy in 
genera or orders of those various forms of pollen, which have been 
described in detail by Mohl, Schacht and others as prevalent in large 
groups, but some of which Mr. Darwin has recently shown to be indi- 
vidual differences in different flowers of the same species,—on the con- 
formity of anatomical structure of the stem with other characters on 
which large groups are formed, which has chiefly occupied the atten- 
tion of French botanists,—and any similar researches would be valu- 
able contributions to our publications, provided their authors do not, 
by attaching an undue or, at any rate, premature importance to cha- 
racters they have thus brought to light, proceed at once to generaliza- 
tion, remodelling the whole system of classification, and throwing 
everything into confusion by new names and new combinations which 
can never be safely adopted without re-examining and testing in detail 
that complication of characters upon which the old ones had been 
gradually established. Tabular arrangements of classes, orders, and 
minor groups, regularly defined by new characters, are tempting to 
make, and may look well on a black board ; but if we have hitherto re- 
fused a place in our Transactions to those which have been offered to 
us, and if I do not here allude in particular to any of those which we 
are continually receiving, it is because we have seen no evidence of 
their being more than theoretical speculations, untested by a study of 
the innumerable exceptions which Nature offers to all our systems. 
And on this head I cannot resist applying to our own Transactions 
and Proceedings the words of Cuvier, prefixed to the Nouvelles Annales 
du Muséum, in 1832 :—“ L’expérience leur a appris, que ce qui dans 
des recueils de ce genre conserve un intérét durable, ce que les 
savants consultent longtemps encore aprés la publication, ce sont les 
descriptions exactes et les bonnes figures d’espéces nouvelles, les 
caractéres nouveaux découverts dans les espéces anciennes et propres 
4 en rendre la distribution plus naturelle, ou la détermination plus 
précise, les faits nouveaux bien constatés dans leur histoire, les détails 
positifs et bien décrits de leur anatomie...... enfin tout ce qui, une 
fois consigné par. écrit, demeure comme une partie intégrante de la 
science. Chacun peut s’appercevoir, au contraire, que les pures con- 
ceptions de lesprit, les dissertations théoriques, les hypothéses 
variables au gré de l’imagination qui les erée, en se renversant l’un 
Vautre d’année en année, quelqu’éclat qu’elles puissent jeter, quelque 
bruit qu’elles puissent faire au moment ot elle paraissent, tombent 
