In range it extends from Iowa to British Columbia and southward in the Rocky Mountains to New Mexico.

Eupatorium rapunculoides, n. comb. Stevia rapunculoides DC. Prod. v. 124 (1836). Eupatorium dasucarpum Gray, Proc. Am. Acad. xxii. 420 (1887); Robinson, ibid. xxxvi. 478 (1901).

EUPATORIUM REMOTIFOLIUM DC. Prod. v. 165 (1836). This species is reduced without comment by Baker in Mart. Fl. Bras. vi. pt. 2, 205 (1876) to E. Vitalbae DC., but the two species in question have not the smallest resemblance. It can only be inferred that Mr. Baker was misled through some transposition of labels or similar slip. The plants are by no means similar in habit, leaf texture, inflorescence, or involucre. The marked difference in the size of the heads is quite sufficient to show them distinct species. In E. Vitalbae the florets, including the mature achene, are 10-12 mm. long, while in E. remotifolium they are, when measured in the same manner, only 4-5 mm. long.

Eupatorium resinosum Poepp. [& Endl.] Nov. Gen. et Spec. iii. 54 (1845), not Torr. From an examination of the type-specimen of this obscure species, which is to be found in the herbarium of the Imperial Natural History Museum at Vienna, it is clear that it is identical with E. LAEVIGATUM Lam. Dict. ii. 408 (1786).

EUPATORIUM RUBRICAULE HBK. Nov. Gen. et Spec. iv. 124 (1820). Although excellently described by Kunth, this species appears never to have been recognized. Hemsley (Biol. Cent.-Am. Bot. ii. 100) refers no material to it beyond the original specimen collected by Humboldt & Bonpland, and no more recent collection of it seems to be on record. The type was found, however, to be exactly the plant for some years known as E. amplifolium Gray, Proc. Am. Acad. xv. 28 (1880), and well shown by the following exsiccatae: Parry & Palmer's no. 334 from San Luis Potosi, Pringle's no. 4272 from cool cañons near Pazcuaro, Michoacan, Palmer's no. 165 (coll. of 1902) from Alvarez, San Luis Potosi, and L. C. Smith's no. 858 from the mountains of Jayacatlan, alt. 2150 m., Oaxaca. Dr. Gray's later specific name must, of course, drop into synonymy. Why E. rubricaule HBK., which is a large-leaved perennial, should have been referred to E. guadalupense Spreng. by the Index Kewensis is not clear.

EUPATORIUM SAGITTATUM Gray, Pl. Wright. i. 88 (1852). This species has in general ovate-oblong sagittate or hastate leaves considerably longer than broad. In its wide deltoid leaves the following plant is strikingly different, although maintaining the essential characteristics of the species.

Var. deltophyllum, n. var., fruticosum oppositirameum habitu

capitulis involucri squamis formae typicae simile; foliis multo latioribus deltoideis 3-4 cm. longis 2-4.4! cm. latis apice et angulis inferioribus transverse divaricatis acutis. Near Culiacan, Sinaloa, Mexico, coll. Schaffner (type, in hb. Gray).

EUPATORIUM THYRSOIDEUM Moc. ex DC. Prod. v. 150 (1836). Some years ago the writer (Proc. Am. Acad. xxxvi. 484) stated the belief that this plant was identical with E. quadrangulare DC. 1. c. However, subsequent study of more copious material and a re-examination of the type specimens in the Prodromus Herbarium at Geneva have shown conclusively that the two species are wholly distinct notwithstanding considerable habital resemblance. To E. thyrsoideum, which may be recognized by its roundish stem, more glomerate-thyrsoid inflorescence, and softer less stramineous involucral scales, the following specimens may be referred: Dr. Palmer's no. 1048 (coll. of 1890) from Manzanillo, and his no. 1162 (coll. of 1891) from Colima, W. G. Wright's no. 1355 from San Blas, Langlassé's no. 650, collected on granitic soil at Cajinicuilar, alt. 300 m., in Michoacan or Guerrero, Baker's no. 2302, Volcan El Viejo, Dept. Chinandega, Nicaragua, and Barclay's no. 2719 from Tiger Island, Gulf of Fonseca.

Eupatorium tolimense Hieron. in Engl. Bot. Jahrb. xix. 45 (1894). The writer, after examining the type of this species at the Royal Botanical Museum at Berlin and the type of E. PELLUCIDUM HBK. Nov. Gen. et Spec. iv. 108 (1820), which is preserved in the herbarium of the Museum of Natural History at Paris, is unable to find any differences of importance between them.

EUPATORIUM URTICAEFOLIUM Reichard, Syst. iii. 719 (1780). Ageratum altissimum L. Spec. Pl. ii. 839 (1753). Eupatorium altissimum Murr. Syst. Veg. ed. 13, 614 (1774), not L., nor Murr. 1. c. 613. E. ageratoides L. f. Suppl. 355 (1781). Kyrstenia altissima Greene, Leafl. i. 8 (1903). A consistent application of the rules of priority necessitates the reviving of Reichard's name for our common and attractive North American Eupatorium which has long passed as E. ageratoides. Furthermore, in consequence of this revival of Reichard's E. urticaefolium, it is necessary to suppress the later E. urticaefolium L. f. Suppl. 354 (1781). This, however, is no great misfortune, for the species of Linnaeus filius has been in recent times entirely misinterpreted, the name having been applied by English and German botanists to a coarse annual, widely distributed in tropical America, having rather long pedicels and ovate-lanceolate to lance-linear leaves. This plant has borne many names, of which the earliest appears to be the hitherto obscure E. pauciflorum HBK. Nov. Gen. et Spec. iv. 120 (1820). Very different from this is the type of E. urticaefolium L. f.,

which is still extant in the herbarium of the Linnean Society of London. It is a Colombian plant, apparently perennial, with deltoidovate, strongly cordate leaves and contracted inflorescence, the pedicels being very short. It is not yet certain whether this plant has received a later name, but it is pretty close to E. ballotaefolium HBK. and of course has nothing whatever to do with the E. urticifolium of the Flora Brasiliensis or of recent writers on the flora of Argentina and Paraguay.

MIKANIA BADIERI DC. Prod. v. 194 (1896). This excellent species is well marked by its coriaceous glabrous essentially entire leaves, which are rather abruptly acuminate, ending in a caudate and often falcate tip. The petioles are furthermore much flattened and rather broad. The species, notwithstanding these distinctive characters, has been reduced by Grisebach (Veg. Karaib. 85) to M. latifolia J. E. Smith (Rees, Cyclop. xxiii. n. 8). Grisebach also implies that it is suspiciously close to M. amara Willd. However, the inflorescences in M. Badieri are pyramidal panicles in which the heads are subspicately arranged, while both in M. amara Willd. and in M. latifolia J. E. Smith (ex char.) the heads are borne in corymbs. In the herbarium of Lamarck there is a sheet of M. Badieri labelled in the hand of Lamarck himself "Eupatorium vincaefolium Lam. dict. no. 39 de Mr. Badier de la guadeloupe No 137." At first sight it would appear that this was an authentic type of E. vincaefolium Lam. and that his earlier specific name should take the place of DeCandolle's later Badieri. However, Lamarck did not cite the plant of Badier in his Dictionary, but on the other hand distinctly states that his E. vincaefolium was founded on South American material. Indeed, most of the characters are evidently drawn from Aublet's plate and description of E. parviflorum, which Lamarck reduces to a synonym of his own species. Although Badier's plant of Guadeloupe possesses some habital similarity to the South American one, the latter lacks the broad petioles and the peculiar acumination and is doubtless a distinct species. Obviously, it is to the South American plant that Lamarck's name E. vincaefolium was applied.

Mikania Houstoniana, n. comb. Eupatorium Houstonianum L. Spec. ii. 836 (1753). E. Houstonis L. Syst. ed. 10, 1204 (1759). E. fruticosum Mill. Dict. ed. 8, no. 6 (1768). Mikania Houstonis Willd. Spec. iii. 1742 (1804). The rule of priority of the specific name requires the restoration of the earlier adjectival form.

BRICKELLIA ATRACTYLOIDES Gray, Proc. Am. Acad. viii. 290 (1870). Of this species, Coleosanthus venulosus A. Nelson, Bot. Gaz. xxxvii. 262 (1904), is an exact synonym.

BRICKELLIA MICROPHYLLA Gray, Pl. Wright. i. 85 (1852); Bulbostylis microphylla Nutt. Trans. Am. Phil. Soc. n. s. vii. 286 (1841). To the synonymy of this species may be added B. cedrosensis Greene, Bull. Torr. Bot. Club, x. 86 (1883); Coleosanthus cedrosensis Greene, Erythea, i. 54 (1893).

BRICKELLIA OBLONGIFOLIA Nutt. Trans. Am. Phil. Soc. n. s. vii. 286 (1841). Of this species, Coleosanthus humilis Greene, Pittonia, iv. 124 (1900), appears to be a synonym.

Brickellia paniculata, n. comb. Eupatorium paniculatum Mill. Gard. Dict. ed. 8, no. 15 (1768). E. Verae-Crucis Steud. Nom. ed. 2, i. 609 (1840). Ageratum paniculatum Hort. and Eriopappus paniculatus Hort. ex Steud. 1. c. Eupatorium rigidum Benth. Pl. Hartw. 88 (1841), not Sw. Brickellia Hartwegi Gray, Pl. Wright. i. 85 (1852). Miller's Eupatorium paniculatum seems never to have been studied or accurately identified. It is evident that Steudel's renaming of the species was purely a bibliographical change incident to his compilation, and involving no personal examination of the plant. Miller's type, collected at Vera Cruz, Mexico, by Dr. Houston, is still extant in the herbarium of the British Museum of Natural History, and proves to be the plant which has for some time been passing under the name of Brickellia Hartwegi Gray. There seems no reason why Miller's name should not be restored and transferred to the correct genus. Steudel's purpose in renaming E. paniculatum Mill. (1768) was doubtless that he might maintain the better known but much later homonym of Schrader (1832), which, however, has since proved a synonym of E. microstemon Cass. Link, Enum. ii. 306 (1822), erroneously united under the name E. paniculatum the very different plants of Miller and Schrader, belonging as we now see to two distinct genera. The unwarranted name E. Verae-Crucis still persists in some botanical gardens.

Cacalia asclepiadea L. f. Suppl. 352 (1781). Senecio (?) asclepiadeus DC. Prod. vi. 422 (1837). This doubtful species from Colombia seems never to have been studied or accurately placed. Fortunately the type-specimen is still extant in the herbarium of the Linnean Society of London. It proves to be identical with Eupatorium angustifolium Spreng. Syst. iii. 415 (1826); Mikania angustifolia HBK. Nov. Gen. et Spec. iv. 138 (1820). Although the Linnaean specific name is older, it cannot be applied in Eupatorium because of the existing homonym, E. asclepiadeum DC. Prod. v. 148 (1836). Cacalia asclepiadea L. f. should therefore drop into the synonymy of EUPATORIUM ANGUSTIFOLIUM (HBK.) Spreng. and the genus Cacalia (or Senecio) may thus be freed from a dubious species.

Proceedings of the American Academy of Arts and Sciences.

VOL. XLII. No. 2.-JUNE, 1906.

CONTRIBUTIONS FROM THE JEFFERSON PHYSICAL LABORATORY, HARVARD COLLEGE.

ARCHITECTURAL ACOUSTICS.

I. INTRODUCTION.

II. THE ACCURACY OF MUSICAL TASTE IN REGARD TO ARCHITECTURAL ACOUSTICS.

III VARIATION IN REVERBERATION WITH VARIATION IN PITCH.

BY WALLACE C. SABINE.