surface between pyroxene and felspar, suggest that this 

 surface existed prior to the crystallisation of the pleonaste. 

 The pleonaste fibres as they pass into the centre of the 

 pyroxene areas become thickened and twisted, bending 

 about in a peculiar fashion, and irregular blebs of pleonaste 

 may lie across the boundary surface between two pyroxene 

 crystals. (See Plate 34, fig. 3, also fig. 8.) Moreover there 



3— Olivine gal 



)bro with pleonaste. 



little "chut 



es" of pyroxene containing 



)ut between 



two felspar crystals. The 



spinel running 



pleonaste in these rocks does not occur unassociated with 

 pyroxene, it does not, for instance, form independent inclu- 

 sions in the felspar. All of these observations show that 

 the pleonaste has formed subsequently to the felspar, a 

 reversal of the normal order of consolidation. 1 



A very interesting feature occurs in a slide kindly lent 

 me by Mr. J. L. Froggatt ; here four pyroxene individuals, 

 apparently all monoclinic, have intercrystallised in a poiki- 

 litic fashion, and pleonaste has crystallised in a semi-grano- 



' Barker, Natural H^t-.rv ..r r-n- „, K- -ks, p. 205. 



