In the northern part of Argentina .the transi tion from the rainy to the dry season is very marked. A four-season climate prevails in Corrientes, Entre Rios, Santa Fe, Cordoba, Buenos Aires, Mendoza, San Luis and the re maining country lying south. However, there is always a prevalence of rains from October to April. In the provinces of Corrientes, Salta, Jujuy, Catamarca and Santiago del Estero and the territories of Chaco, Formosa, Andes and Misiones, climatic conditions are those of sub tropical countries. In Buenos Aires, Santa Fe, Entre Rios, La Rioja, San Juan and San Luis, south of Corrientes, Santiago and Catamarca and territories of La Pampa Neuquen and Rio Negro, the climate is temperate. In Santa Cruz, Tierra del Fuego and Chubut, the climate is cold but not so severe as to pre vent these southeastern regions from being habitable.
The highest recorded temperature, 120°, was during the hot wave of February 1900, in the province of Catamarca at the extreme north, and the lowest recorded temperature was 3°, in the southern extremity of the continent, a range of 117° of temperature in 33 degrees of latitude. The Argentina weather bureau states, however, that lower temperatures are probably experienced in the interior of the territory of Santa Cruz. In the northern part of the Litoral the ordinary range of temperature is from to 106° and in the southern section of the Litoral the usual limits are from 32° to This is the territory in which most of the corn is raised and the summer temperature averages from 72 to 77° and is rarely above 96°.
The meteorological system of Argentina con sists of 200 meteorological and 1,600 rain-gauge stations. Besides, the Argentine Weather Serv ice receives from 12 Brazilian, 10 Chilean and six Uruguayan stations. The i Argentine weather' map issued daily shows conditions from Para (Brazil) to the southernmost limit of the continent. At the South Orkney station (lat. S.) there is a fully equipped meteorological and magnetic station. The hydrometric service has estab lished 150 river gauges and information is published in the daily weather map as to the depth of the water at the principal ports and shallow passes of the navigable rivers as well as timely warnings of the apptoitch of the freshets in the rivers. The magnetic service is well equipped for the observation of the solar spots and spectroscopic observations, atmos pheric electricity, kite work and the prepara tion of the isogonic chart of the country.
Geology.— In the Tertiary period the up lifting of Cordilleras and of the Andes was effected, and the leveling of the Pampas, giving to the country the physical aspect of to-day. The Pampean system is characterized by the abundance of deposits of an argillaceous sand of great fineness, of gray color peculiar to de posits of sand and clay or alumina, the first of which encompasses the slopes of the Sierras, while the second is found along the margin of the Plata. The Pampean system is character ized, moreover, by an abundant and marvelous fauna of fossil mammals.
The works of Florentino Ameghino, who collected hundreds of fossil specimens on the banks of Patagonian rivers, will help m clear ing up many points related to the origin and distribution of mammals, man included. The fact that most of the fossils appear in forma tions older than those in which the same species are to be found in the northern hemi sphere is leading some paleontologists to assign man an antiquity not hitherto suspected. In this connection the finding in 1914 by a com mission from the Buenos Aires Museum of Natural History of an arrowhead — evidently the work of man—embedded in a bone of Tox odon remains one of the most sensational pale ontological discoveries of the age. To compre hend the abundance of fossil mammals in Pam pean soil it is necessary to remember that in the Cretacean epoch the southern hemisphere contained relatively more land than water; while in the northern hemisphere the con trary condition existed. This naturally greatly favored the deposit of a varied fauna of mammalia.
The Cretacean epoch is represented in Ar gentina by the Chubutian and Guaranitican formations, which belong respectively to the lower and upper Cretacean. The former ex tends over the territory of Chubut, occupying the most central part, and is characterized by a very hard sand of very marked color. Both land and marine fossils are found in it. The latter formation is found in Corrientes and Misiones, reappearing in the Rio Negro and also in Chubut, resting upon the former.
The period of the Tertiary epoch is repre sented along the coast of Patagonia and sea shore region from Puerto Madryn to the bot tom of the Gulf of Nuevo, as far as the mouth of the Santa Cruz River, where it disappears under the Atlantic. The fossils are marine on the coast, and land toward the west. To the south of Patagonia, between the rivers Chico and Gallegos, there extend other formations of the same period.