Filling the gaps in the army, raising it from a peace to a war footing, was an easier matter. The Italian military law provided automatically for this increase. Every Italian citizen able to bear arms is liable to military service. Recruits are called in the year during which they become twenty years old, although volunteers are accepted as young as eighteen. The last Italian census, in 1911, gave Italy a population of 34,686,683 and the levy lists of that year totaled 487,570. By the close of the year 1914, when the mobilization began, it is reasonable to suppose that the population had grown to something like thirty-six or thirty-seven million, with a corresponding increase in the number available for military service. The peace strength of the army was 14,000 officers and 271,000 men. Mobilization added to each of the twelve corps a division of Mobile Militia bringing its strength up to 37,000 men and 134 guns. The army's war strength was about 700,000 in the first line--from the two classes of the regular army--and 320,000 in the Mobile Militia with a reserve of more than 2,000,000 in the Territorial Militia. The force of trained men that Italy put into the field at the beginning of hostilities, therefore, numbered something over 1,000,000 men. The reservoir of the Territorial Militia contained twice as many more untrained men who for some reason or other were exempt from military service in times of peace, although physically fit to be soldiers. This class was designed primarily for garrison duty, guarding railways and bridges, but in war time was liable to any service. When the mobilization began the men of this class immediately went into training. Each of the twelve army corps consisted of two divisions of line infantry, a regiment of Bersaglieri (light infantry corresponding to the French Chasseurs and the German Jaegers), a regiment of cavalry, a section of Carabinieri (military police), thirty-six field guns and from two to three heavy howitzer batteries. In addition there was the ammunition column, telegraph and engineer parks, ambulance and supply sections, reserve store and supply sections, and a section of field bakery. The famous Alpine troops ("Alpini") and the mountain artillery were not within the organization of the twelve permanent army corps. These numbered seventy-eight companies, each of 256 officers and men on a war footing. The rest of the Italian infantry units at normal war strength were as follows: Company, 255 officers and men; Battalion, 1,043 officers and men; Regiment, 3,194 officers and men. Five of the cavalry regiments contained six squadrons, the rest five. The war strength of a squadron was 142 officers and men.