434 cook: pomegranate flowers 



magnesian silicate minerals, since it is essentially absent from such 

 rocks as peridotites of which olivine is the chief mineral and the 

 iron is ferrous oxide. It seems probable as has been suggested 

 by Kemp 15 that V 2 3 may be present in titaniferous magnetites 

 replacing some of the ferric oxide, and he has remarked on the 

 extremely sympathetic relations of Cr 2 3 and V 2 3 in the same 

 ores. 16 



A second fact which at least is suggestive is that the chemical 

 analyses of rutiles that have been made under the direction of the 

 writer indicate that difference in depth of color is probably not 

 to be attributed to iron oxide. On comparing the percentages 

 of iron (FeO) with those of vanadium (V 2 3 ) in the table above it 

 will be observed that vanadium increases with decrease of iron, 

 and the color increases in depth in the same direction. In other 

 words the rutile (I) containing highest FeO and lowest V 2 3 is 

 red in color, while the rutile (III) showing lowest FeO and 

 highest V 2 3 is nearly black; II is intermediate in color and shows 

 less FeO and more V 2 3 than I. 



No conclusions of course can be drawn for rutiles in general 

 since complete analyses of the mineral are exceedingly few, but 

 the above results are suggestive and it will be of interest to ascer- 

 tain whether the possible relation holds in future analyses of rutile. 

 Sufficient work has been accomplished by recent students, how- 

 ever, to indicate that in future analyses of rutiles careful search 

 should be made for both vanadium and chromium. 



BOTANY. — Pomegranate flowers dimorphic. O. F. Cook, Bureau 

 of Plant Industry, U. S. Department of Agriculture. 



The flowers of the pomegranate are of two forms that can be 

 distinguished by the shape of the buds long before the time of 

 opening. The buds that are to produce perfect flowers and set 

 fruit appear more cylindrical than the others, because they have 

 a larger base and are usually more abruptly rounded below. The 

 other buds are shorter, with a narrower and more tapering base, 

 and a general shape that may be described as obconic or turbinate. 



15 Kemp, J. F., Trans. A. I. M. E., 40: 862. 1910. 



16 Kemp, J. F., 19th Ann. Rept. U. S. Geol. Survey, Pt. Ill, p. 396. 1897-98. 



