24 The Microscope. 



face without perceptible distortion. The brightness of the paper is 

 regulated by smoke-tinted glasses, which fit into the prism mounting. 

 The apparatus is specially adjusted for the No. 2 Huyghenian eye- 

 piece ; mounted on this, affixed by a clamping-screw, the mirror only 

 requires turning in the proper position, and it is then ready for use. 

 — Am. Naturalist. 



Preparing Tendon-Cells and Cells of the Loose Subcutane- 

 ous Tissue. — Dr. A. Dogiel {Anat. Anzeig., 11, 1887) obtained 

 very good preparations of tendon, by placing a rat's tail in Gren- 

 acher's alum-carmine for two or three hours, or better still, for a 

 week or even a month. The tendon bundles swell up and become 

 transparent, and the cells appear beautifully stained. The elastic 

 fibres stand out very clearly. The same effect may be obtained if 

 tendon be placed in a saturated solution of potash or ammonia-alum, 

 and afterwards stained with Grenacher's carmine, alum-logwood, 

 hsematoxylin, eosin, etc. Mounted in glycerine, the preparation 

 keeps for a long time, but afterwards a slight decoloration takes 

 place. Permanent prepai'ations of tendon are better placed in spirit, 

 then oil of cloves, wherein they are teased out, then dammar or 

 balsam. For the subcutaneous tissue it is recommended to take a 

 piece fi'ee from fat from the inguinal or abdominal region of a 

 mammal, and having spread it out, to stain with a concentrated 

 solution of fuchsin, diluted with an equal volume of water, and then 

 stain under the cover-glass, where the preparation lies in half -per- 

 cent, solution. For permanent preparations picro- carmine, glycerine. 

 — Jr. E. M. Society. 



ABSTRACTS 



A PAEASITIC EOTIFER. 



NEARLY twenty years ago, E. Ray Lankester briefly described 

 and roughly figured a rotifer, which he found parasitic 

 in the body-cavity of Synapta, from the island of Guernsey. 

 Recently Dr. Zelinka has found the same form in the Adriatic, and 

 describes it as a Discopus synaptcB nov. gen. et sp. According to 

 the latter author, this is not an endo-parasite, but lives in folds of 

 the skin of the Synapta, and from these large numbers may be taken 

 by a pipette. The animal belongs to the pJiilodinidce. Zelinka 

 has been able to stain and section these animals, and describes their 

 internal structure in some detail. His conclusions are (1) that the 



