124 



ous equations containing many rmkno^vn quantities, x, y, z, . . . . Different 

 pliases of tlie natural system viewed from diiferent standpoiuts are to be 

 likened to different equations showing the different relations of the unknown 

 quanties ; and tlie natural relations wliich we are struggliug to demonstrate in 

 constructing a uatural system are somewhat similar to the values of the un- 

 knowu quautities wliich satisfy the equatious. This metaphor, I tliink, makes 

 sufficiently clear that a natural system should be a dynamic one. 



The characters which Engleb refers to in §§ 16, 17, 18, and 19'^ as those 

 denoting the stages of advancement, are all the respective peculiarities of the 

 plants and they should certainly be taken into account. 



In § 20*^ he states that the whorl arrangement of floral elements usually 

 occurs in correlation with the inferior ovary or zygomorphy. It is true tliat 

 the more the characters come in Hnkage, the less dynamic becomes the 

 system, which shows the natural relations of the plants c^mpared. Consa- 



in tlie CentrospermjD ; Melfistomnceae in the Myrtiilorfe ; Lcntibularinceje anrl others in the Tubi- 

 flowe ; and Plantftginaceaa in the Plantaginales. 



SbCRKTOBY CEIXS, OP VABIOUS SHAPES, WITH BKSINOaS (oILY), LATBX-UEB OB OrHBR CONTESTS, 



are fonni in the followlng families respectively : Calyoaathaca.-e an 1 othsrs in the Ranales ; 

 Papaveracete nnd othera in the Bhoeadales; Bixnceas in the Parietales; Polygalacefe nnd others 

 in the Gernninles ; Sajtindacece and others in the SapinrLales ; Leguminosfe and others in the 

 Epsales ; Myrtaceoe and others in the Myrtiflorie ; Cornace?e in the Urabelliflorae ; Rnbiaceje 

 and others in the Rubiales ; Compositte and others in the Campanulatfe ; Plumbaginaceoe in the 

 Plumbaginales ; Primulacese and others in the Primuliiles ; Aiwsynncere and others in the 

 Contortae; Convolvulaceae and others in the Tubiflorae ; Aristolochiaceae in the Aristolochiales ; 

 Pipemcese nnd others in the Pipemles; Myristicaceae and others in the Ranales; Euphorbiacere 

 and others in the Geraniales; and Moraceae in the Urticales. 



E£,ongat*:d seceetoby sacs are found in the Trocho<lendracene and others in the Banales ; 

 Anacartliaceae in the Sapindales ; Crassulacene and others in the Eosales ; Passifloracese in the 

 Parietales ; Kubiiiceae nnd others in the Bubinles ; Compositte nnd others in the Cnmpanulatie ; 

 Polygonaceje in the Polygonales ; Myristicacere in the Eanales ; and Euphorbiaceae ia the Geraniales. 



Tannin iDioBLASTs arc found in the Yiolacea; and others in the Farietales ; Gteraniacese in the 

 Geraniales ; BliamnacxjjE nnd others in the Ehnmnales ; Leguminosre in the Bosnles ; Melnstomnceaj ; 

 in the Myrtiflorje ; Rubiac^oe in the Rubiales ; Pirolacere in the Ericales ; Gentianaceae in the 

 Contortse ; Solanacete and others in the Tubiflorie ; Polygonacese in the Polygonales ; Aristolo- 

 chiacete in the Aristolochiales ; Piperaccfe in the Piperales ; Euphorbiacene in the Geramales ; 

 Moraciere in the Urtioales ; and Ceratophyllncefe in the Eanales. 



iNTBAXTiiABT PHLOEii is f ound in the f oUowing f arailies : Vcxihysiacese in Qernniales ; Combretacese, 

 Myrtacese, Melastomataceae and others in the Myrtiflorae ; Cucurbitacepe in the Cucurbitnles ; Apocy- 

 nace£B and others in the Contortae ; Convolvulacefe and others in the Tubiflorje ; Basellaceai in 

 the CentrosjjermsB ; Polygonac^ese in the Polygonales ; and Euphorbiaceaj in the Gemniales. 



1) Engleb, A. — I. c. pp. XIV. XV. 2) Engleb, A. - 1. c. p. XV. 



