362 



SCIENCE 



[N. S. Vol. XLIV. No. 1132 



The specimens described here were obtained 

 along Bolin's Creek. Some were taken near the 

 inner margin of the zone and some near the creek 

 at the foot of Glover Hill. The primary minerals 

 as shown by the microscope are oligoclase, horn- 

 blende, quartz, magnetite and apatite named in 

 order of their abundance. The apatite occurs as 

 inclusions. The oligoclase contains innumerable, 

 minute inclusions occupying most of the area of 

 the crystals except in the narrow marginal zone 

 which are entirely free from them. The parallel 

 striations are in general very narrow and very 

 close together and in some of the zones are in- 

 visible. The order of crystallization is as follows: 

 apatite, magnetite, hornblende, oligoclase and 

 quartz. The secondary minerals are epidote, and 

 a small quantity of albite. They are derived from 

 the oligoclase, magnetite and hornblende by hy- 

 dration. 



The quartz decreases in amount outward from 

 the center of the stock. The lime in the water 

 supply of Chapel Hill is produced from this feld- 

 spar. The soils derived from the rocss of this 

 zone constitute the Iredell series and contain little 

 or no potash. 



Physiography of the Isle of Palms (S. C.) : E. 



Oscar Eandolph. 



The Isle of Palms, situated eight miles to the 

 northeast of Charleston, and connected with that 

 city by a trolley line, has an area of approxi- 

 mately 4,000 acres. This sea-captured land is 

 about six and one fourth miles in length, and one 

 and one fourth miles in maximum width, tapering 

 to a decided point at the southwestern end. 

 Physiographically this area is interesting and in- 

 structive. In shape it approximates a ham; and 

 by local fishermen it is called ' ' the ham. ' ' 



From the mainland the island is separated by 

 a narrow inlet that is wide and deep enough to 

 convey local freight-, pleasure- and fishing-vessels. 

 This back beach is subjected to no unusual geo- 

 logical agencies except tidal work. The front 

 beach is subjected to wave, tidal, wind and lit- 

 toral current agencies. As a result, frequent shore- 

 line configurations are effected. The writer made 

 a number of instructive observations relative to 

 immediate changes of epicontinental shelving be- 

 tween the points of high and low tide respectively. 



Two well-defined sand dune ridges traverse the 

 island lengthwise. Physiographically, incipient, 

 migratory, temporary and fixed dunes are in evi- 

 dence. Among the flora are found sand arresters 

 and dune fixers. The front beach is continuously 

 attacked by wind and wave action; the interdune 



area is likewise undergoing change under the in- 

 fluence of wind-trough currents and animal life. 

 The age and stability of the fixed dunes, ranging 

 in height from twenty-five to forty feet, is real- 

 ized in their supporting luxuriant palm trees. 



Alternation and Parthenogenesis in Padina: 



James J. Wolfe. 



At the meeting of this academy in 1913, the 

 writer made a preliminary report on this work. 

 It had then been carried only to the point of dem- 

 onstrating that tetraspores invariably produce 

 male and female plants. The entire series has 

 now been completed, showing with equal certainty 

 that fertilized eggs produce only tetrasporie 

 plants — thus demonstrating "alternation of gen- 

 erations" in Padina. 



In view of the fact that Padina grows well only 

 in localities where it normally occurs, in the ex- 

 periments dealing with parthenogenesis, clean 

 oyster shells were attached alongside those bearing 

 unfertilized eggs to serve as controls. The results 

 of both series were in essential respects sufficiently 

 similar to show that all plants recovered were in 

 both cases derived from chance reproductive bod- 

 ies. Thus, it is fairly conclusively shown that un- 

 fertilized eggs, though they germinate quite freely 

 parthenogenetically, never produce mature plants. 



No abstracts have been received for the follow- 

 ing papers: 



"Friday Noon," by George W. Lay. 



"Zonation in the Chapel Hill Stock," by Collier 

 Cobb. 



" Eussula xerampelina; a Study in Variation," 

 by H. C. Beardsley. 



' ' Improvements in the Method of Determining 

 the Heating Value of a Gas," by C. W. Edwards. 

 (By title.) 



"Magnetic Separation of Minerals," by Joseph 

 Hyde Pratt. 



' ' Insect Polyembryony, " by E. W. Leiby. 

 (Lantern.) 



"An Apparatus to Illustrate the Cohesion of 

 Water — with Reference to the Ascent of Sap," by 

 P. E. Carruth. (By title.) 



"Some Becent Feeding Experiments with Cot- 

 tonseed Products," by W. A. Withers and F. E. 

 Carruth. (By title.) 



"A Study of Some Nitrifying Solutions," by 

 W. A. Withers, H. L. Cox, F. A. Wolf and E. E. 

 Stanford. (By title.) 



' ' A New Industry for North Carolina, " by C. 

 P. Williams. (By invitation.) 



E. W. Gudgee, 



Secretary 



