100 Years Ago
It is well known that when America was discovered maize was widely cultivated by the aborigines, but the wild source of the plant has remained obscure. Various views concerning its origin have been entertained, one being the theory of Mr. Collins, based on breeding experiments and morphological comparisons, that maize arose as a hybrid between the Mexican teosinte (Euchlaena) and some unknown grass belonging to the Andropogoneae. Mr. Y. Kuwada … has studied the chromosomes of maize and its relatives, and brings cytological evidence in support of Mr. Collins’s hypothesis. Maize, as well as Euchlaena and Andropogon, is found to have ten pairs of chromosomes, but those of Euchlaena are longer than those of Andropogon, while in maize they are found to be of different lengths, a pair frequently being composed of a longer and a shorter chromosome. From this it is concluded that maize is hybrid in origin, the two types of chromosomes being traceable as in certain experimentally produced animal hybrids.
150 Years Ago
The work done by the Sea is infinitely various, immeasurable in quantity and of inexpressible value to the inhabitants of the earth. It is the one ceaseless worker, never resting and ever accomplishing the tasks it has to perform. The land and the sea may appear to some to be for ever fixed and unalterable, and the map of the world represents to them the geography of the globe of 6,000, or 60,000 years ago, the geography of to-day, and the geography of 60,000 years hence. Still not only does Geology show by the testimony of the far-distant past the impossibility of this being so; but it has been given to man to see and record the constant rising and falling of the land, within the periods of history and even to measure the movement with sufficient accuracy and such certainty as to enable him to venture predicting, to some extent, on the probable geography of the future. The Earth is born of the Ocean. Continents and islands rise out of the sea, new, luxuriant and vigorous; and like ourselves they grow, mature and do their appointed work; then wane and seem to die, though they do not die. They sink beneath the waves, apparently for ever; but only to be regenerated, renewed, quickened into life and born again remodelled. And the sea — the invigorating and ever-toiling Mother — works this wonder.