XXXV.] 



THE TESTtS. 



3*7 



spiral filament is in reality the optical expression of a thin membrane 

 attached in a spiral direction to the cilium. Mount 

 the spermatozoa of a frog. The male frog is easily 

 known by the wart on his thumb. Open the 

 abdomen, and low down in the hollow on each 

 side of the vertebral column is an oval, kidney- 

 shaped, whitish body the testis. It is to be 

 treated like the testis of other animals. At 

 certain seasons of the year no spermatozoa are to 

 be found. The cells are in a resting phase. 



6. Human Spermatozoa. Mount in glycerine 

 some spermatozoa obtained from a spermatocele 

 (tig- 358). Observe the head (&), long tail (/), 

 and middle piece (ra). 



7. Cover-Glass Preparations (H). Compress 

 a small piece of the testis of a newt or frog 

 between two cover-glasses. Separate them, and 

 allow the film on them to dry. Stain one in 

 methylene-blue, and the other for twenty- four hours 

 in Ehiiich-Biondi's fluid. Dry and mount in balsam. 



(a.) In the methylene-blue specimen only the 

 heads of the spermatozoa are stained. In the 

 other, the head of the spermatozoon is stained 

 one colour, while the tail and the intermediary or Fl(i 

 junction piece is of a different hue. 



8. Testis of Salamander. Fix the testis (in September or 

 October) in Hermann's 



fluid, and stain as directed Blood-vessel, 



at p. 384. The bundles of 

 ripe spermatozoa are very 

 marked. The body of 

 each spermatozoon is red- 

 dish, its head bluish-violet, 

 the middle piece also of the 

 same colour, while the tail 

 is brownish - violet. In 

 Hermann's paper figures 

 will be found showing the 

 remarkable stages of de- 

 velopment of the bodies 

 of the spermatozoon from 

 the nucleus of the sperm a- 

 tids. Numerous mitotic 

 figures may be seen. 



9. Epididymis (L and H). Prepare like the testis. 

 T.S., stain in hajmatoxylin and mount in balsam. 



33 8.-Spernia- 

 to/oa. i 2. Human. 



T.S. Tubule. 



Ciliated 



',! epithelium. 



FlQ 359- T.S. Tubules of Epididymis. 



Make 



