thu micrOvScopicai, journal advertiser. 



An Introduction to the study of the Diatoviaceas. By Fred'k Wm. 

 Mills. London and Washington : 8°, 250 pp., Price $3.50. 



Profiting by his experience, the author has sought to make 

 unnecessary much labor on the part of the student, for he has 

 compiled what one requires into small space, as will be seen 

 from the following : 



tabi^E of contents. 



I.^ — Preliininar-y. — What are Diatoms ? — Habitats of the DiatomaccEe. 

 Their extraordinary abundance. — Diatoms form food for aquatic an- 

 imals in the arctic regions. — Found in the digestive organs of fishes. 

 Diatoms in guano. — Fossil Diatoms. — Longevity of Diatoms. Pages i — 3. 



II. — The Structure Of Diatoms. — Gelatinous envelope. — External 

 coating of silica. — Valves. — Diatoms' marking. — Raphe and nodules. — 

 Endochrome. — Nucleus. — Chemical properties of the endochrome ex- 

 amined spectro-scopically. — Oil globules in Pleurosignta. — Molecular 

 movement in the protoplasm. Pages 4-6. 



III. — The 3IoveuietitoJ Diatoms. — Movements observed. — The exist- 

 ence of endosmatic and exosmatic currents. — The existence of cilia on 

 some parts of the frustule. — The existence of a snail-like foot external 

 to the frustule. — Movements caused by a modification of the interchange 

 of gases. Pages 7-15. 



IV. — Classification of the Diatomacecs. — The raphidieae. — The pseudo- 

 raphidieae. — The Crypto-raphidiea?. — Species. Pages 16-38. 



V. — J\[odes of Reproduction. — By simple division. — By auxospores. — 

 By conjugation. Pages 39-42. 



VI. — Collecting Diatoms. — How their presence may be detected. — 

 Free species. — Stipate species. — Frondose species. Methods of collect- 

 ing. — Disintegrating fossil diatoms. Pages 43-45. 



VII. — Mojutting Diatoms. — To \\\o^xu\. in sitic. — Method of preparing 

 frustules for mounting dry, or in a medium.— Mounting dry. — Mount- 

 ing in media. — Methods of charging the markings of Diatoms. — Mer- 

 curous sulphide method. — Silver nitrate method. — Color of final cell- 

 ringing. Pages 46-51. 



VIII. — RJicroscopical Examination of Diatoms. — Microscope stands. 

 — Objectives and Condensers. — The useof a Condenser. — Preparing en- 

 dochrome for examination by a micro-spectroscope. — Cutting sections 

 of valves. Pages 53-59- 



IX. — How to Photograph Diatoms. — The Camera. — The microscope 

 stand. — Objectives, and oculars. — The dark room. — Chemicals. — The 

 illuminant. — Oxy-hydrogeu. — Coal gas. — Paraffin. — Sunlight. — Mono- 

 chromatic light. — Exposure of the plate. — Development. — Printing. — 

 Lantern slide making. Pages 61-77. 



X. — Bibliography Relating to Diato)iiology. — Containing almost every 

 reference to Diatoms up to the present time, arranged alphabetically 

 under the authors' names. — Pages 78-240. XI. — Index. — Pages 241-3. 



