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Show 1 862 CLASSIFICATION. [CHAP. XIII. every nat ura1 f:a mI· ly, I. 8 very unequal. ' and inh some 1c ashe s seems t o b e ent I·r ely lost ·" Again In .. aa'n ot• ehr w·o r c e sa s the enera of the Connaracere "diuer In aving o~e ory m ' ore ogv ari·a , 1·n the ex1'stence or. absence of albumf enh, In the imbricate or valvular restivation. Any one o .t .ese characters sing1 is frequently of more than generlC Im- poi· ta nce, thouOo 'h here even when all taken together they appear 1· n sufficient to separate 0 nest·l· s f rom Co t ndn ·a r·u ·s ." To ive an example amongst ins~cts, In one grea IVISIOn of E.e Hymenoptera, the a;ttennre, as W ~stwood has .r~- ked are most constant In structure; 1n another divi-msioanr th'e y differ n;uch, a~d t h. e a·If f·e rences are o.f qui' te subordinate value In classification; yet no. o?~ p1obably will say that the antennre in . thes~ t'~o diviS1ons of the same order are of unequal physiol?gwalimportance; ~ny number of instances could be g1ven of ~he varying Importance for classification of the same Important organ within the same group of beings. . . Again, no one will say tha~ rudimen~ary ?r atrophied organs are of high physiologi?al or ;~tal Importance ; yet, undoubtedly, organs in this cond~tlo~ are often of high value in classification. N ~ one Will dispute t~at the rudimentary teeth in the upper Jaws of young rl!minants, and certain rudimentary bones of the _leg, are highly se~viceable in exhibiting the close affinity between Ru~nnants and Pachyderms. Robert Brown has strongly Insisted on the fact that the rud~men~ary florets are of the highest importance in the classificatJ.on of the Grasses. Numerous instances could be gi;en of characte~s ~erived from parts which must be co;tsidered of. very tr1fimg hysiological importance, but which are ~n.Iversally ad~ itted as highly serviceable in .the · definition. ~f whole rou s For instance whether or not there 1s an open ~asslg~ from the nostrils to the mouth, tf!e. onl~ character, according to Owen, which absolutely distmguishe~ fish~s and reptiles-the inflection o~ the ang:le of t~e Ja~~- I~ lfarsupials-the manner in wh1ch the wings of Insects aie folded-mere colour in certain Algre-mere pubesfe~~e on the parts of the flower in grasses-:-the nature 0 e dermal covering, as hair or feathers, ln the Vertebrata. OsA.P. XIII.] CLASSIFICATION. 363 ~the Ornit~orh:tnchus had been covered with feathers 1nst~ad of han·, this ext~rnal and trifling character would, I thi?k? have be~n. considered by naturalists as important an aid In det~rmining the. degree of affinity of this strange ?reature to ~nrds and rep~Iles, as an approach in structure 1n any ~ne Internal and Important organ. The Importance, for classification of triflinO' characters mainly depends on their being cdrrelated ~ith several ?ther characters of more or less importance. The value mdeed of. an aggregate of characters is very evident in natural history. l-Ienee, as has often been remarked a species 1nay depart from its allies in several charact~rs both of high physiological importaiJ.Ce and of almost uni~ versal prevalence, and yet leave us in no doubt where it should be ranked. Hence, also, it has been found that a classification founded on any single character l;owever importan~ th~t ~ay b.e, has always failed; for ~o part of the orgamsation Is universally constant. The importance of an aggregate of characters, even when none are important, alone explains, I think, that saying of Linnreus ~at the characters do not g.ive t~e genus, but the genu~ g~ves the characters ; for this saying semns founded on an appreciation of rnany trifling points of resemblance too slight. to. be defined. Certain plants, belonging to' the Malp1ghiace::e, bea~ perfect and degraded flowers ; in the latter, as A. de J ussieu has remarked, "the greater nu1nber of the characters proper to the species to the genus to the f~mil:t, t~, the class, disappear, and thus laugh at ~ur clas.sification. But when Aspicarpa produced in France, dur1ng sever~l years, only degraded flowers, departing so wonderfully In a number of the most important points of st:ucture fro~ the proper type .of the order, yet M. R1chard sagamously saw, as J uss1eu observes that this ~e~us should still be retained amongst the Malpighiace::e. ~~s case seem.s to . me well to i~lustrate the spirit with which ou~ classifications are sometimes necessarily founded. Practically when naturalists are at work, they do not trouble thems.elves about the physiological value of the ch~acters _whw~ they use in defining a group, or in allocating any particular species. If they find a character |