A great series of photographs, Mr. Weima. Congratulations(!) and Thank you for posting this. With regard to the question of the development and incubation of the eggs, the publication: 'True Vipers, Natural History and Toxinology of Old World Vipers'(David Mallow, David Ludwig and Goran Nilson; Krieger Publishiing Company. 2003. ISBN #: 0-89464-877-2) states on page 216 that: (Psuedocerastes) 'Eggs are laid in advanced developmental states, bearing embryos 8.5 cm long with supraorbital horns present. Consequently, egg development is relatively short, lasting 30-32 days at 31(degrees Celcius)'; citing Mendelssohn(1965; On the biology of venomous snakes of Israel. Part II. Isr. J. Zool. 14: 185-212)and Sprawls and Branch(1995; The Dangerous Snakes of Africa. Ralph Curtis Books. Dubai: Oriental Press. 192 pps.). If possible, more photos and updates would be very much appreciated. Sincerely, Jon Davidson .