^*26 TRANSACTIONS OF THE [APRIL l^;, 



the beam of light were allowed to fall near the centre of the dome 

 (see Reflection of Window, Fig. 1) a four-rayed star was observed, 

 but if the light were allowed to fall upon the garnet from the end 

 (see Figure 2), a six-rayed star, or ratner a form resembling two 

 crosses with joined arms, was the result. However, if the centre 



Natural size. 



of the garnet were shaded so that a strong light came from each 

 end, an eight-rayed star was the result (see Fig. 3.), showing 

 that the 4, 6, or 8 rays were simply tlie effect of one or more 

 beams of light condensed by the network of included crystals.. 



Natural size. Natural size. 



The occurrence of these crystals in this net- or lattice-work form' 

 (see "Transactions" for Dec, p. 7G), and the observation that, 

 especially in Nortli Carolina, rutile frequently occurs in quartz 

 and other materials in this same form, although in larger crys- 

 tals, together with the occurrence of geniculations in garnets- 



