158 



JOURNAL OF THE [Julv, 



THE BLACK CROSS OF THE SUGAR PINE. 



The Rev. J. L. Zabriskie : "The object exhibited is the lon- 

 gitudinal-radial section of the wood of Pimis Lambertiaiia, 

 Dougl., the Sugar Pine of the western slopes of the mountains 

 on the Pacific coast. The popular name is due to an occasional 

 use of a sweet exudation from the stump of the tree, as a 

 substitute for sugar. 



" I desire to mention especially the appearance of the 'len- 

 ticular markings ' of the section, as shown by polarized light. 

 These markings are in the Sugar Pine about .001 of an inch in 

 diameter — the largest of any of the coniferae, as far as I am 

 aware. By polarized light — in common with the similar mark- 

 ings in all the coniferze — they show a distinct, diagonal, black 

 cross. But, either on account of their large size, or some pecu- 

 liarity of their structure, the black cross is shown with unusual 

 distinctness in the markings of this tree. 



" Dr. Thomas Taylor, of the Agricultural Department at 

 Washington, has called my attention to the fact of the similarity 

 of this cross to the cross of the crystals of butter. If you turn 

 to his beautiful representations of the photomicrographs of the 

 butter crystal, in the Ainerican Monthly Microscopical Journal, 

 for August, 1887, you will see how striking this similarity is. 



" I take pleasure in donating the slide to the Cabinet of the 

 Society." 



WOODY STRUCTURE IN COAL. 



Mr. p. H. Dudley : " This section was prepared by the late 

 Dr. Allen Y. Moore. The woody structure shown is identical 

 with that of Sequoia gigantea, the Giant Tree of California." 



The President, Mr. Charles F. Cox, read a Paper, entitled 

 " Notes on the Thread-cells of certain ccelenterate Animals," 

 which Paper is published in this number of the Journal, p. 131. 



Mr. J. D. Hyatt, in remarking upon his exhibit, stated that 

 the prominences upon the skin of the Chameleon are not, properly 

 speaking, papillae, but scales, which are covered with smaller 

 scales, and that these smaller scales are marked with fine dots, 

 averaging about 4,500 to the linear inch ; that each main scale, 

 in those parts of the body where change of color appears, has a 

 rib, like a stout spine, embedded longitudinally in its outer sur- 

 face ; and that the change of color is produced by the elevation 



