Journal of Applied Microscopy. 



201 



that most o£ its parts are of glass, avoid- 

 ing any danger from the effects of metals 

 on the tissues. 



A. Kolossoro suggests a method for 

 investigating epithelium by using injec- 

 tions of the following mixture into the 

 vascular system of a newly killed animal, 

 in which the system has been washed 

 out with normal salt solution: 



Osmic acid, 5 per cent sol. in water, 

 100 CO. 



Saltpeter 30 per cent. sol. in water, 

 5-1 cc. 



Glacial acetic acid, Ice. 



Nitrate of Potash, 10-12 grms. 



After two to three minutes, the injected 

 part or organ is cut in small pieces and 

 put for sixteen to twenty-four hours in 

 ten per cent, tannin solution, which fluid 

 is changed as often as any blackening is 

 seen. The tissue is then washed in 

 water and put in 70 per cent., 85 per cent., 

 and 96 per cent, alcohol. It is cut in 

 parafHn, and no staining is necessary. 

 The points particularly well shown are 

 the cell bridges. 



M. Catois gives as a successful method 

 of making neuroglia preparations by put- 

 ting the tissue into osmic bichromate 

 for ten to twenty hours, not for longer. 

 In this tissue only the neuroglia cells are 

 impregnated, and show sharply. 



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 montli pre- 

 ceding issue. 



Professor L. L. Lewis, Oklahoma Agri- 

 culLural College, writes regarding the 

 preparation of Agar where the autoclave 

 is not a part of the laboratory equipment, 

 as follows: " I have found it very diffi- 

 cult to filter Agar or Gelatin and have 

 finally adopted the following method: 

 use the white of an egg to free the media 

 from sediment as near as possible, then 

 pack the funnel full of absorbent cotton, 

 first running through distilled water 

 until the cotton forms a smooth, even 

 layer in the funnel. Pour in the media 

 while hot, and it will filter through clear 

 and almost as rapidly as water." 



For fixing zoophytes and polyzoa with 

 their tentacles extended, Kleinenberg's 

 picro sulphuric acid has been used. The 

 animals are allowed to assume their 

 natural position in a small quantity of 

 water, when they are quickly deluged 

 with a stream of the solution. This is 

 continued until the water becomes a 

 deep yellow. The specimen n:iay then be 

 removed, carried up through the differ- 

 ent grades of alcohol and stained with 

 any of the common stains. Picro carmine 

 has been used with success. 



The Indiana University, Biological 

 Station, under the direction of Dr. Carl 

 Eigenman, closed its work of the sum- 

 mer on Friday, August 19th. It con- 

 tinued during two terms of five weeks 

 each, and there were engaged thirteen 

 instructors and assistants. The follow- 

 ing data show the remarkable success 

 and growth of the station, since its 

 establishment in 1895: 



1895—19 students enrolled, 1 state 

 represented. 



1896—32 students enrolled, 4 states 

 represented. 



1897 — 68 students enrolled, 5 states 

 represented. 



1898 — 105 students enrolled, 8 states 

 represented. 



Demonstration of the Flow of Latex in 

 the Stipules of Ficus Elastica. — The 

 lactiferous vessels can readily be seen 

 in the large red colored, deciduo.as 

 stipules of Ficus elastica. The stipules 

 envelop the young leaves in the bud, 

 and, before falling off, they become 

 somewhat transparent. If one of these 

 stipules is removed a few days before it 

 is ready to fall, the lactiferous vessels 

 can be seen very distinctly by simply 

 holding it on the stage of the microscope 

 with its under surface up, and examin- 

 ing with the two-thirds and one-sixth- 

 inch objectives. Since the latex will be 

 flowing from the torn end of the stipule, 

 the movement in the ducts will often be 

 quite rapid, and appear not unlike the 

 circulation of blood in the capillariess. 

 Of course, the student must be cautioned 

 that the movement of the latex is due 

 entirely to the fact that it is flowing out 

 of the open vessels, otherwise the im- 

 pression might be obtained that the latex 

 had a circulatory movement. J. H. S. 



O. S. U. Bot. Lab. 



Nuclear division in Spirogyra has re- 

 cently been thoroughly investigated by 

 L. Mitzkewitsch.* After an admirable 

 discussion of the work of previous in- 

 vestigators, he gives his own results. 

 The nucleolus, which in Spirogrya has a 

 definite membrane, seems in the resting 

 condition to be homogenous, but as di- 

 vision proceeds is seen to consist of in- 

 tensely staining granules— the Chromo- 

 somes — and a less deeply staining sub- 

 stance, perhaps linin. The nucleolar 

 membrane soon disappears, and the 

 nucleolus puts out granular processes 

 which reach to the periphery of the 

 nucleus. These pi'ocesses are soon with- 

 drawn and achromatic threads appear 

 within the nucleus, apparently a con- 

 tinuation of achromatic threads which 

 have appeared in the polar plasma heaps 



*Flora, Band 8.5 pp. 81-124, 1898. 



