36 THE MICROSCOPE. Marcli 



the stem. Figures r, s, and t, show single frustules of 

 the same plant floating freely and reveal different mark- 

 ings and positions. Pinnularia major (fig. e) is a common 

 diatom. It has three nodules, one in the centre and one 

 at either end. The ribs are large and conspicuous. Pin- 

 nularia viridis (fig. g) has the sides of the valves more 

 convex than Pinnularia major, and is smaller and, although 

 green by name, it is brown in color. 



Figures n and o represent two different forms of Pleu- 

 rosigma. This genus may be recognized by its beauti- 

 ful curvature, resembling the letter S (the word Pleu- 

 rosigma means S-shaped). It has a line extending 

 lengthwise with a nodule in the center. The lines on the 

 striated valves are quite close together and difficult to 

 see except with a high power objective of good construc- 

 tion. 



National Science Club. 



The second annual meeting of the National Science 

 Club was held Jan. 2 — 3, 1896, in the Science Reading 

 rooms and hall of the National Museum at Washington, 

 D. C. The object of this club is to create and increase an 

 interest in science among the women of our land and it 

 has in its membership many of the most intelligent scien- 

 tific students and specialists. The following are the titles 

 of some of the papers read at the meeting : 



Lake studies by the President, Mrs. R. S. Eigenman, 

 Bloomington, Ind. (Illustrated with lantern slides.) 



Sense organs of Lumbricus agricola, Miss F. E. Lang- 

 don, Michigan University. 



Fermentation in Bread, Growth of Plants, Miss K. E. 

 Golden, Purdue University. 



Vitality of Plants, Mrs. E. S. Bladen, Philadelphia, Pa. 



The Duty of the Women of the State to its Public 

 Schools and Universities, J. H. Smith, M. D. 



