Proceedings of the 2nd International Congress of Acaro-logy, Sutton Bonington (England) 19th-25th July, 1967. Spermatogenesis in ticks [Dermacentor, Amblyomma, Aponomma, Anocen-for, Rhipicephalus, Boophilus, Haemaphysalis and Ixodes] used for biological and microbiological investigations (Abstract).