The spermatogenesis and spermatozoa of mammals are of funda- mental interest to a wide variety of academic and scientific disci- plines; zoologists keep up interest in comparative biology of sper- matogenesis and spermatozoa in different groups of mammals for determining their phylogenetic interrelationships. Therefore, during the past 15 years, a wealth of reviews and papers have been published on the morphology (including ultrastructure), histochemistry, auto- radiography, biochemistry (including immunology), and cell physiol- ogy of the seminiferous epithelium including Sertoli cells,...

In 1954, when I obtained my B. Sc. (Honours School) degree in Zoology, I was asked by my advisor, the late Professor Vishwa Nath, to make comparative cytological studies of oogenesis in birds for my M. Sc. (Honours School) thesis submitted to the Panjab University in 1956. Using the classical techniques of cytology, I studied the various aspects of follicle growth and atresia in five species of birds. Professor Vishwa Nath, who himself devoted most of his life to the study of the comparative cytology of gametogenesis in animals, was so much impressed by my findings on avian oogenesis that he...