784 REGINALD ALDWORTH DALY 
are caught up from the surrounding terranes.t In many cases, 
however, it is due not only to differential cooling, but to the 
pulling of the horses along in the direction of the migrating 
viscid magna. Such is the case with the examples of the cir- 
cumferential arrangement of feldspars noted on Sandwich 
Mountain, on Saddle Hill, and in the Fitzwilliam area, and else- 
where. 
4. Many observers have described the orientation of horses 
parallel to the margins of contact in cases where the inclusions 
have distinct elongated form.? The latter condition is usually 
furnished in the case of fragments derived from a country-rock 
with plane-parallel-structure. Consequently, we can understand 
this very general marginal arrangement described in all of the 
principal areas.3 i 
5. The greater the heterogeneity among the constituents of 
the igneous body at the time of proximate consolidation, the 
more pronounced will be the flow-structure. As suggested by 
Bonney,* horses may be melted up and thus give local variations 
in the mineralogical constitution of the igneous body. ‘‘ Band- 
ing’’ is sometimes produced by the imperfect mixing of more 
tLawson, The Geology of the Rainy Lake Region; Ann. Rep. Geol. Surv. 
Canada, 1887-8, F’, 137-138. BARLOW, op. cit., p.29. DAKyYNs and TEALL, On the 
Plutonic Rocks of Garabal Hill and Meall Breac; Q. J. Geol. Soc., 1892, p. 106. 
Koto, B., The Archean Formation of the Abukuma Plateau; Jour. Coll. Sci. Imp. 
Univ., Tokio, 1893, p. 288. GREGORY, Q. J. Geol. Soc. 1894, p. 242. 
2 DUROCHER, Mém. de la Soc. Géol. de France, 2° sér., t. VI. See his descrip- 
tions of several gneiss-granite contacts in Scandinavia; LEHMANN, Untersuchungen 
tiber die Entstehung der altkryst. Schiefergesteine. Bonn, 1884, pp. 16, 21; GEIKIE, 
A., op. cit., p. 39; GRANT, U.S., Field observations on certain granitic areas in north- 
eastern Minnesota; 20th Ann. Rep. Minn. Surv., 1891, p. 40. 
3Cf. EMERSON, Bull. Geol. Soc. Am., I, 1890, p. 559. 
4Geol. Mag., 1894, p. 119. Cf. BONNEY, zézd., 1894, p. 118. C. CHELIUS has 
recently described a stage leading to the complete fusion of enclosed masses, which is 
of interest. In this case granite cuts diorite and includes so many lenses of the latter 
in parallel arrangement as to simulate a “grobflaseriger gneiss.’’ Notizbl. d. Ver. f. 
Erdk. Darmstadt, IV, Folge, 14 Heft, 3-8, 1893. Ref. in Neu Jahrb., 1895, p. 72. 
J. J. SEDERHOLM speaks of “Schlieren” rich in mica and garnets in the “ druck- 
schieferiger Granit” of Finland. They are taken to represent remnants of schist- 
inclusions which have been dynamically metamorphosed. Om Borggrunden i Sodra 
Finland, 1893. Ref. in Neu. Jahrb., 1895, p. 335. 
