Among the ammonites of the Jurassic and Cretaceous periods types occur which in their external appearance so closely resemble each other that they could be taken for members of a single series, and not infrequently have been taken for species of the same genus and even for the same species; but their early stages of development and, in fact, their entire individual history prove them to be distinct and not infrequently to belong to widely separated genetic series.
The principal step in the modern development of algebra was the recognition of the meaning of negative quantities.
But with the systematic development of the vast mineral resources of the South Wales coalfield, the population of Glamorganshire has increased at a more rapid rate than that of any other county of the United Kingdom, so that at present this county contains about half the population of all Wales.
The conception of the development of the plan of the earth from the first of cooling of the surface of the planet throughout the long geological periods, the guiding power of environment on the circulation of water and of air, on the distribution of plants and animals, and finally on the movements of man, give to geography a philosophical dignity and a scientific completeness whici it never previously possessed.
Although this diversion of the stream may be an artificial development of a natural channel, and undoubtedly dates from a period long prior to recent Persian occupation, it appears that the later arrangements have been more maturely and better organized than those carried on by the predecessors of the amir of Kaian.
He thinks that there is a notion of understanding (Verstandesbegrif), under which every new experience is subsumed, but that it has been developed by former experience, instinctively, and by the development of the race, as part of the economy of thinking.
The peaceful development of Athenian power was interrupted by the revolt of Samos in 440.
The lopeared breed is the oldest English variety, and has been cultivated carefully since about 1785, the aim of the breeder being directed to the development of the size of the ears, and with such success that they sometimes measure more than 23 in.
The most striking development in the resources of the country from 1909 was the exploitation of the copper mines of Katanga.
The deep-sea and coast fisheries of Ireland form a valuable national asset, which still admits of much development and improvement despite the fact that a considerable number of acts of parliament have been passed to promote and foster the fishing industry.