96 THE AMERICAN MONTHLY [Apr 



as perfect coaditioa, but these are certaiuW saflBcieut to 

 emphasize the claim I have made for this solution, name- 

 ly that as a killing and fixing solution it will yield, as it 

 has yielded, excellent results. 



What advantages are to be gained by the use of this 

 solution ? Briefly, these : In a large laboratory where 

 fixing solutions are almost constantly used, and where 

 the quantity as a consequence becomes great, decrease in 

 expense is an item well worth considering. Here form- 

 aldehyde as a fixing solution proves invaluable, for it 

 not only answers the purpose of other and more expen- 

 sive solutions, but it also possesses the valuable proper- 

 ty of preserving its strength when kept for some time. 

 It may be made up in large quantities and used when de- 

 sired withoutanydimimution of its effectiveness. Finally, 

 while this may not be the best or most perfect formula 

 that can be prepared from formaldehyde, I am confident 

 that others trying it will find that it will give satisfac- 

 tory results, and the future will accord formaldehyde a 

 prominent place as a fixing agent. 



Miscellaneous Notes on Microscopy. 



JOHN. H. COOKE, F. L. S., F. G. S. 



Light. — When photographing bacteria and other minute 

 organisms, the cone of light should never be reduced by 

 stopping down. Without a full sized cone of light, white 

 diffraction lines will appear around the organism. 



Herrings. — Mr. Henry F. Moore, of the United States 

 Fish Commission, has recently published the results of 

 his investigations on the food of herring. The staple diet 

 of these fish consist of minute organisms, often of micro- 

 scopic dimensions. Examinations of the stomachs of the 

 fish showed the food to consist largely of copopods,schiz- 

 opods (shrimp-like forms), amphipods (sand fleas and their 

 allies), the embryos of gasteropods and lamellibranchs, 



