OCTOBEB 16, 1896.] 



SCIENCE. 



573 



is divided. One-half is sour, like a Greening, and 

 the other half is sweet, like the Tallman. This is one 

 of the most peculiar freaks which has ever been ob- 

 served in vegetation. Its oddity, as well as its fine 

 bearing qualities, and the excellent quality of the 

 fruit, both the sweet and sour portion, will make it 

 immensely popular." 



I also send for your examination a Dahlia 

 stem bearing two flowers of different colors. 

 E. Lewis Sturtevant. 



South Feamingham, Mass., October 6, 1896. 



[The one Dahlia is light pink, becoming 

 darker towards the center, the other dark 

 maroon with a few pink petals near the center. 



Ed.] 



the limits of science. 



President Mees, in his address before Sec- 

 tion B (Physics) of the American Association for 

 the Advancement of Science (printed in the last 

 number of this Journal) states that the prog- 

 ress of science " may be expressed by a curve 

 approaching truth asymptotically, probably 

 never in human experience approaching to its 

 complete knowlege. So long as investigators 

 find that they are working upon the steep part 

 of the curve where it approaches truth rapidly, 

 there is no lack of interest ; this, however, 

 seems to die out quickly when much labor and 

 great patience are required to extend experi- 

 mentally the curve now more slowly approach- 

 ing complete knowledge, or straighten out some 

 of its irregularities. ' ' 



I should myself regard the progress of science 

 from a very different point of view. Knowledge 

 does not seem to me to approach final truth as 

 an asymptote, but rather to be an irregular 

 sphere in endless space. The more we enlarge 

 our little sphere the greater is the surface at 

 which our knowledge touches our ignorance. 

 The more we learn the greater is the area im- 

 naediately awaiting exploration. 



It is true, as President Mees states, that a 

 man or group of men of unusual insight carry 

 forward our knowledge, and the details must 

 be filled in until the average has arrived at 

 the point reached by the positive variations. 

 Then new positive variations carrying our 

 knowledge further are more likely. But there 

 has never before been a time when it was pos- 



sible for a man of genius to make such great 

 advances and in so many directions. 



J. McKeen Cattell. 

 Columbia University. 



rutgers college museum. 



To THE Editor of Science : The Geo. H. 

 Cook Museum of Geology occupies the two 

 upper stories of Geological Hall, which was 

 built in 1871. The museum proper is 84 feet 

 long, 40 feet wide and about 23 feet high, with 

 a gallery 6 feet wide on all sides. The upper 

 and lower class rooms open directly into the 

 museum by double doors. 



The Cook collection of minerals occupies six 

 cases on the east side of the room, and numbers 

 over 4000 specimens. The fossils, and speci- 

 mens illustrating geology, are arranged in six 

 cases on the west side, which, with two large 

 cases on the floor, of rocks, iron and zinc ores, 

 clays, sands and marls (including fossil bone& 

 and shells found in the marls) of New Jersey, 

 number 5250 specimens. 



The Lewis C. Beck collection of minerals fills 

 two large cases on the floor^ and contains 3000 

 specimens, mostly collected over fifty years ago. 

 Many of them are the original specimens used 

 in some of the old State reports and text-books, 

 and it is really a historic collection of great 

 value to the mineralogist. The pseudomorphs 

 are specially valuable to the lithologist and 

 mineralogist. The center of the floor is occu- 

 pied . by a case of Ellenville quartz crystals, 

 showing also crystals of Chalcopyrite, Sphale- 

 rite and Galenite. This collection is a gem ! 



On the floor near the entrance is a mass of 

 Jura-'Trias sandstone 8x18 feet, from Morris Co. , 

 N. J., showing fifteen species of dinosaurian 

 footprints. This is said to be the largest and 

 best specimen of saurichnites in this country. 



The Mannington (N. J.) mastodon, which 

 was set up last June, covers a space 8x20 feet 

 at the north end of the room. 



A diamond-drill core in the gallery shows a 

 section of the rock at the Franklin zinc mines^ 

 1378 feet in depth. 



Cases are being built for the large collection 

 of paleolithic implements numbering about 1500 

 specimens, which include many fine pipes and 

 ceremonial and ornamental objects. 



