concept of Mesolithic as best he could, but the public could see that his methods were not typological. The less prestigious scientists publishing in the smaller journals continued to look for a Mesolithic. For example, Isaac Taylor in The Origin of the Aryans, 1889, mentions the Mesolithic but briefly, asserting, however, that it formed "a transition between the Palaeolithic and Neolithic Periods". Nevertheless, Sir John fought on, opposing the Mesolithic by name as late as the 1897 edition of his work. Meanwhile, Haeckel had totally abandoned the geologic uses of the -lithic terms. The concepts of Palaeozoic, Mesozoic and Cenozoic had originated in the early 19th century and were gradually becoming coin of the geologic realm. Realizing he was out of step, Haeckel started to transition to the -zoic system as early as 1876 in The History of Creation, placing the -zoic form in parentheses next to the -lithic form. The gauntlet was officially thrown down before Sir John by J. Allen Brown, speaking for the opposition before the Anthropological Institute on 8 March 1892. In the journal he opens the attack by striking at a "hiatus" in the record: It has been generally assumed that a break occurred between the period during which ... the continent of Europe was inhabited by Palaeolithic Man and his Neolithic successor ... No physical cause, no adequate reasons have ever been assigned for such a hiatus in human existence ... The main hiatus at that time was between British and French archaeology, as the latter had already discovered the gap 20 years earlier and had already considered three answers and arrived at one solution, the modern. Whether Brown did not know or was pretending not to know is unclear. In 1872, the very year of Evans' publication, Gabriel de Mortillet had presented the gap to the Congrès international d'Anthropologie at Brussels: Between the Palaeolithic and Neolithic, there is a wide and deep gap, a large hiatus. Apparently prehistoric man was hunting big game with stone tools one year and farming with domestic animals and ground stone tools the next. Mortillet postulated a "time then unknown (époque alors inconnue)" to fill the gap. The hunt for the "unknown" was on. On 16 April 1874, Mortillet retracted. "That hiatus is not real (Cet hiatus n'est pas réel)," he said before the Société d'Anthropologie, asserting that it was an informational gap only. The other theory had