206 



THE MUSEUM. 



of the silk-worm also, as this spinner 

 has been known to thrive and breed 

 when housed during cold weather, and 

 has been repeatedly kept in the active 

 state under glass; that is, in extensive 

 winter gardens. 



Any of my readers may keep a series 

 of cocoons and regulate the time for 

 their hatching by exposing them to the 

 sun and warmth of summer, or keep- 

 ing them in a cool spot and thus re- 

 tard the completion. 



It is suggested that students attempt 

 to keep over some of our larger com- 

 mon cocoons, and see if activity can be 

 prevented for an extra twelve-month. 

 This can be tried by placing some co- 

 coons deep down in an ice-nouse, or 

 better still in a cold storage house. 

 The cocoons should be secured in a 

 tightly closed tin box to prevent moist- 

 ure from affecting the live pupa;. 



Let us hear of your success, or lack 

 of it, through these columns. Exper- 

 iments with turtles and snakes in the 

 same direction will also be of great in- 

 terest. Morris Gibes, 



Kalamazoo, Mich. 



Some Crystallized Micas of North 

 Carolina. 



By E. H. Harn. 



Among the many minerals of inter- 

 est to the collector and student found 

 from time to time in the older meta- 

 morphic rocks of the Western counties 

 of North Carolina, there are none 

 more unique, and few inaeed that are 

 really handsomer than recent discover- 

 ies in the mica group. 



Perfect tabular hexagonal crystals 

 with all the prism planes full, clear- 

 cut and brilliant have been found lat- 

 ely in some quantity. The most 

 abundant form of these specimens are 



groups of crystals of all sizes, with one 

 to three planes fully developed, and 

 planted in every conceivable angle of 

 penetration, so that specimens as tak- 

 en from the vein matted and not 

 crumbled, have a more or less globul- 

 ar appearance and a general radiation 

 from a common center. 



But while this is the rule for its oc- 

 currence as far as exploited, there was 

 one notable exception. This was a 

 single pocket or vein opened in the 

 Western part of Lincoln County, and 

 all of the material taken out was in 

 peefect six-sided single crystals. If 

 there was any grouping, it was made 

 up by the penetration of one or more 

 crystals into and through another, and 

 all showed the full number of planes. 



In this vein the penetrations which 

 were common in all other deposits ob- 

 served, were very rare. Here, how- 

 ever, the mica was much decomposed, 

 and but a few crystals out of the many 

 hundreds obtained were in any degree 

 clear. 



The color most common is green of 

 some shade, from deep emerald clear 

 and transparent in all positions, to 

 dark bottle green and lighter to oil 

 green and nearly yellow. 



In one case all of the mica obtained' 

 from a pocket of clear and amethys- 

 tine quartzes was a clear reddish brown. 

 The crystals were all penetrations one- 

 half to three-quarter inches in diam- 

 eter, showing two to four planes and 

 very brilliant. The amount secured 

 here was very insignificant, a few 

 ounces. 



In my operations no vein carrying 

 mica crystals has been worked lower 

 than ten feet, but they show every in- 

 dication of being true fissure veins. 

 When abandoned they still continue to^ 



