92 Spermatozoa. 



fluid will adhere to the slide, to this add a small drop 

 of glycerine and gently mix the two fluids. Cover and 

 examine. 



To STAIN NEWT'S SPEKMATOZOA. 



After having washed away all traces of the chromate 

 of ammonia, make an incision into the testis nearly 

 dividing it, and place it in undiluted logwood stain for 

 an hour or more, then wash away all superfluous stain 

 and mount in glycerine. Spermatozoa may be double 

 stained, but it is a very tedious process, as a little too 

 long immersion in either stain spoils the whole pro- 

 cess. The best way is, after washing off the super- 

 fluous logwood stain, to dip a portion of the testis in 

 undiluted spirituous solution of rosein ; a little must be 

 mounted to see if the stain is deep enough, if not it 

 must be dipped again. 



It is possible in this way to get spermatozoa of newt 

 or salamander with the long pointed head stained with 

 rosein, while all the other parts are stained with log- 

 wood. 



MAMMALIAN SPEKMATOZOA. 



To make preparations of mammalian spermatozoa, 

 a little glycerine is placed in a watch-glass, and one or 

 two drops of absolute alcohol added. A cut is then 

 made into the globus major of a fresh testicle, and a 

 little of the fluid removed on the point of a knife and 

 placed on a slide ; a small drop of the glycerine is then 

 mixed with it, it is then covered and sealed with HolhV 

 glue. 



