254 THE AMERICAN MONTHLY [Aug. 



MICROSCOPICAL MANIPULATION. 



An Experiment. — Take some dust from the gutter of your 

 roof and put it in a little tank of water. Examine it under the 

 microscope daily. Perhaps you will find a Rotifer, an Amoeba 

 or an Infusoria. 



To Mount a Leaf of Deutzia. — Boil in nitric acid and 

 chlorate of potash until the leaf is tender. Then take off the 

 epidermis with needles, stain it with ha^matoxylin. After 

 washing, dehydrate it with alcohol. Clean it with oil of cloves. 

 Mount in balsam. 



DIATOMS. 



To give some idea who have been the great writers upon the 

 diatoms we have counted up the number of articles by each 

 cited in the ]Hbliograi)hy which is attached to Mills' Introduc- 

 tion to the stud}' of the Diatomacete. We omit those who are 

 cited less than ten times. 



C. G. Ehrenberg, Berlin. 152 



A. Grunow, Anvers. 102 



Conte Astracane, Rome. 81 



Rev. E. O'Meara, London. 63 



Fred Kitton, London. 60 



G. B. DeToni, Venezia. 40 



Paul Petit, Paris. 33 



.Julian Deby, England. 32 



H. L. Smith, Geneva, N. Y. 32 



J. W. Bailey, New Haven, Conn. 32 



L. Rabenhorst, Dresden. 28 



K. K. Greville, Edinburg. 26 



A. M. Edwards, Newark, N.J. 26 



H. Van Heurck, Brussels. 25 



.J. Pelletan, Paris. 25 



Matteo Dott Lanzi, Rome. 21 



E. M. Nelson, London. 19 



Charles Stodder, Boston. 18 



Otto Muller, Berlin. 16 



W. Gregory, M. D., London. 15 



