48 THE MICROSCOPE. [March. 



What known locality is richest in variety of fossil Diatoms t 



The California deposit that includes Monterey, Santa Monica, 

 and Los Angeles. This is marine. 



What in fresh-water diatoms ? 



The fresh-water diatoms are fossil and recent. Any of those 

 in the East of the United States — fossil — as at Bowkerville, N. 

 H.. called " Keene " and " Troy" deposits. The brackish diatoms, 

 fossil, are found at Newark, N. J., and the fresh-water at Hat- 

 field Swamp. X. J. 



What causes determined the quantity of diatoms in any given 

 deposit y 



I cannot answer this unless it is more definite. 



Divini's Microscope. — We are indebted to Mr. E. G. Love, 

 of New York city, for the following : 



I notice on the cover of The Microscope illustrations of three 

 old instruments, the first being Divini's. dated 1657. This 

 evidently is from Schott's Magia Universalis, and is one of 

 several forms which are represented as of enormous size. The 

 one in question, for instance, must have been from 6 to S feet long. 

 It has always seemed to the writer that this cut gives a wrong 

 impression regarding the size of this old microscope ; and I 

 think we must agree with the opinion expressed by the late Mr. 

 Mavall, that the illustration does not represent the instrument as 

 constructed. Mr. Crisp has suggested that the draughtsman 

 who prepared the cuts for Schott's work probably knew noth- 

 ing about microscopes, and instead of representing an eye look- 

 ing into the tube, he drew the full-length figure, which gives such 

 a ludicrous effect. 



This explanation seems the more probable inasmuch as in 

 Traber's JVervus Opticus, also refered to by Mr. Mavall, what is 

 evidently the same instrument is figured with the eye only. 



RECENT PUBLICATIONS. 



Proceedi?tgs of the American ^Microscopical Society. Edited by 

 the Secretary. Part I, October ; Part II, January, pp. 1-132. 

 On the Sth of March, 1S93, we were very much pleased to 

 receive these two parts of the report for 1892. Part I contains 

 the minutes, the constitution, presidential address, and papers 

 by Ewell, Biscoe, Claypole, Griffith, Holbrook, Kraiiss, Kelli- 

 cott. and Rowles. Part II contains papers by Sternberg, Bell, 

 Gage, and Rogers. The place for the next meeting will be 

 either Madison or Chicago. 



