Journal of Applied Microscopy. 



223 



development of bacteria. These state- 

 ments apply only to water bacteria. He 

 recommends a 20 per cent. water-pep- 

 tone-Koch-gelatin; a five per cent, gela- 

 tin may be used for testing filters. He 

 also recommends the use of iron salts for 

 the culture of pathogenic bacteria. He 

 used among others a ten per cent. Liq. 

 ferri alb. 



L. H. Pammel. 



Inaug. Diss. Kiinigsberg, 1898. 



Is the Bacterium Cell Nucleated? 



Opinions differ among bacteriologists 

 as to whether the bacterium cell is nucle- 

 ated. Migula holds it is not, and in sup- 

 port of his position has reinvestigated 

 Meyer's Astasia asterospora, Meyer hav- 

 ing described a very small nucleus 

 (Kornchen). Migula holds that these 

 "Kornchen" are similar to those occur- 

 ring in Bacillus oxalaticus, B. cereus, and 

 B. megaterium. There may be a single 

 one of these bodies in a cell or more than 

 one. They originate from the peripheral 

 protoplasm of the wall and in Astasia 

 and other species never divide. They 

 originate in all probability from small 

 Invisible granules that coalesce. A 

 similar phenomenon occurs in the forma- 

 tion of spores. In Astasia he confirms 

 the peculiar spore membrane which he 

 has never observed in other bacteria. As 

 to the peculiar arrangement of the flag- 

 ella, the author was unable to confirm 

 the results of Meyer's work. He calls the 

 orgonism Bacillus asterosporus. 



I. H. Pammel. 



Flora 85 : 141-lo0, f. 1-3. 



NEWS AND NOTES. 



Minor notes on technique, personals, news items, 

 notices of meetings of societies, conventions, etc., 

 will be received up to the tenth of the month pre- 

 ceding issue. 



Yeast. 



Yeast and Spirogyra are as indispen- 

 sable to the botanist as the frog to the 

 physiologist, and any new light upon 

 their internal structure is eagerly wel- 

 comed by teachers who have occasion to 

 use them in laboratory courses. During 

 the past few years much has been 

 learned regarding the nuclei of these 

 organisms. It seems now that the pres- 

 ence of a nucleus has been demonstrated 

 beyond question in most species of Sac- 

 charomyces. Many a teacher has tried 

 to stain the nucleus of yeast cells for 

 exhibition to his students, but in most 

 cases, judging from the number of com- 

 plaints one hears, the attempt has ended 

 in failure. So explicit are the directions 

 given in a recent paper* that it seems 



worth while to reproduce them some- 

 what in detail and to state briefiy the re- 

 sults obtained by their use. 



The authors used Saccharomyces cere- 

 visiae I, Hansen, S. Ludwigii Hansen, 

 and S. Octosporus Beyerinck, together 

 with several other species not identified. 

 Cultures were made in sterilized and 

 well aerated must of 12 degrees to 14 

 degrees Balling, in conical Erlenmeyer 

 flasks, and kept in an incubator at 20 

 degrees C. The cells were fixed in Moel- 

 ler's liquid (100 cubic centimeters of dis- 

 tilled water, one gram of iodide of potas- 

 sium and iodine to saturation). The 

 method of fixation i'^ as follows: several 

 drops of the solution are placed upon a 

 slide, then with the aid of a platinum loop 

 a small amount of yeast is mixed with 

 the liquid and a drop of the mixture 

 placed upon a cover glass and spread 

 around evenly with the loop. The cover- 

 glass must be perfectly clean and free 

 from grease. The preparations are al- 

 lowed to dry in the air, and at the exact 

 moment at which the last of the liquid 

 has evaporated from the cover glass, the 

 latter is quickly immersed in a Petri dish 

 containing Moeller's fluid, the cover of 

 the dish replaced and the preparation 

 left in the fixing agent at least twenty- 

 four hours. It is very important that 

 the cells do not become too dry in the air. 

 At the expiration of the time for fixation, 

 the preparations are passed successively 

 through water, "one-third alcohol," 80 

 per cent, alcohol, and finally into 95 per 

 cent, alcohol. In order to obtain a clear 

 coloration the iodine must be thoroughly 

 removed. This usually takes place in the 

 80 per cent, alcohol, but if it does not one 

 may use a solution of iodide of potassium 

 (1 to 3 parts to 100 of water) or ether. 

 The preparations must remain at least 

 two days in 95 per cent, of alcohol before 

 being colored. They may then be stained 

 at once or may be kept indefinitely in 

 this grade of alcohol. Fixation must not 

 be accompanied by passing the cover 

 glass through the fiame, as is often done 

 with preparations of bacteria. 



Staining may be done according to 

 various bacteriological methods, but the 

 best results are said to be obtained by 

 using Heidenhain's iron-hematoxylin. 

 The preparations are treated for four 

 hours with a solution of 2-5 grams of 

 ferric alum in 100 cubic centimeters of 

 distilled water and then colored for 

 twelve to eighteen hours in 0.5 grams of 

 hematoxylin in 100 cubic centimeters of 

 distilled water. When properly decolor- 

 ized, the preparations now show the 

 nucleus to be stained intensley black, 

 while the cytoplasm remains colorless or 

 has a faint violet tint. 



The stained preparations may be 

 mounted in 50 per cent, glycerine, but the 



