PLATE 



y 



PHOTOMICROGRAPHS 



a. Normal bull semen; photographed in ultraviolet light at 2750 A. 



Mag. X 2700. 

 h. Semen from an infertile bull; the spermatozoa are 'unripe' and show 



kinoplasmic droplets at the anterior ends of the middle-pieces; 



nigrosin-eosin stain. 



