Accordingly, if E be the energy of the primary wave, dE 87-2n (D' - D) 2 T2 E dx 3 D2%4 ' whence E = Eoe-**hx** (II) where h = 8?r 2 n (D' - D)2T2 3 D2 x 4, (12) If we had a sufficiently complete expression for the scattered light, we might investigate (12) somewhat more directly by considering the resultant of the primary vibration and of the secondary vibrations which travel in the same direction.

Though the T **hx**, thoracic segments bear the wings, no trace of these appendages exists till the close of the embryonic life, 8 `' nor even, in many cases, till much later.

(aixi+a2x2)"`=4, and the direct stitution xi = XXi -, LX2, X2 =, **hX** replacing cos 0, sin 0 respectively.

He was the author of an 'Eirvro o' TWv **HX** aTcwos Soy s6TC.wv, an analysis of Plato's philosophy according to later writers.