-150 Journal of Applied Microscopy 



CURRENT ZOOLOGICAL LITERATURE. 



CHARLES A. KOFOID, University of California. 



Books and Separates of Papers on Zoological Subjects should be Sent for Review to Charles A. 

 Kofoid, University of California, Berlteley, California. 



Van Wijhe, J. W. Eene nieuwe Methode ter ^^^ ^^t^or has made successful prep- 

 Demonstratie van Kraakbeenige Mikroske- _ '^ ^ 



letten. Vers), d. Wis. en Natuurk. Afd., arations of the Cartilaginous skeleton 

 834-S37, 1902. Qf Amphioxus, of the embryos of the 



shark and ray, of the salmon and roach, of the frog, lizard, bird, mouse, rabbit, 

 and man. Most basic anilins have an affinity for cartilage and methylen blue 

 was selected after experiment as the most satisfactory for use in this method. 

 The embryos were usually fixed in 5 per cent, sublimate to which yL vol. of 

 formol is added before using. Other agents such as 10 per cent, formol, 

 Zenker's fluid, or simple alcohol gave good results. Even partially disassociated 

 embryos were utilized. When iodine-alcohol is used after sublimate it is advis- 

 able to get rid of the iodine, which otherwise forms an insoluble precipitate with 

 the methylen blue. It may be removed by alcohol containing 5^ per cent. HCl 

 renewed each day until no trace of yellow tint forms in the alcohol. The 

 embryos are stained in alcoholic methylen blue prepared as follows : alcohol 

 100 parts, HCl 1 part, methylen blue }( part. The acid causes the formation 

 of needle-like crystals and should therefore be added some time before using 

 the stain. The stain is allowed to act for 1 to 7 days and is then washed 

 out in the above mentioned acid alcohol until stain is no longer extracted 

 by the decolorizer. There is no danger of over-extraction. The cartilage in 

 embryos left in acid alcohol for over a year remained a bright blue. A week 

 suffices for most embryos, and, at the close of the process, all tissues but cartilage 

 should be colorless. The process may be hastened by alternating 70 per cent, 

 and a stronger alcohol. Dehydration is followed by a gradual transfer from 

 absolute alcohol to xylol, by thin and then thick balsam in xylol and by inclusion 

 in balsam which becomes liquid at 60°, this last step being completed in a ther- 

 mostat. Permanent mounts are made in this medium in built up glass cells. 

 The author uses only the solid neutral Canada balsam of Griibler to avoid the 

 turpentine found in commercial solutions. Preparations in balsam for two years 

 have shown no tendency to fade. Macroscopic museum preparations of shark 

 embryos 20 cm. long, preserved in xylol were exceedingly beautiful at first, but 

 later the non-cartilaginous tissues lost their transparency and became opalescent. 



c. A. K. 



Prenant, A. Notes cytologiques : VI. For- Many standard fixing agents were used, 



mations particulieies dans le tissu coniunctif 1 , ^1 1 ^ i, 1 ^ • j r^ 



interestitiel du muscle vesical du Brochet. ^ut the best results were obtamed after 



VII. Contribution a I'etude de la ciliation Perenyi's fluid and the formol-picric 

 de la partie adherente du Myxidium lieber- . ^ j- -r. • a ^- r ^ 



kuhni. Arch, d' Anat. Micr. 5 : igi-aij.pl. mixture of Boum. A very satisfactory 



ix, 1902. triple stain was obtained by following 



Heidenhain's iron haematoxylin with 

 methyl eosin or with erythrosin. The surplus stain is washed from the slide with 

 water and the sections are treated with Lichtgriin in strong aqueous solution. 

 Nuclear chromatin and other structures retaining the haematoxylin lake retain 

 their deep black color, the protoplasm of the smooth muscle fibers has a rosy 

 tint, while all intermuscular connective tissue is green. The author commends 

 it highly as a general differential staining method. c. a. k. 



