XI.  Now Crassus was afraid that Spartacus might form a design to march against Rome; but he was encouraged by many of the followers of Spartacus quitting their leader, in consequence of some disputes, and encamping by themselves upon the banks of the lake Lucanis,[36] which they say is subject to changes, at certain intervals becoming sweet, and then again salt, and not potable.  Crassus coming upon this band, drove them from the lake; but he was prevented from cutting them to pieces and pursuing them, by the sudden appearance of Spartacus, who checked the flight.  Crassus had, before this, written to the Senate, to say that they ought to summon Lucullus[37] from Thrace, and Pompeius from Iberia; but he now changed his mind, and made every effort to put an end to the war before they arrived, knowing that the success would be attributed to him who came last, and brought help, and not to himself.  Accordingly, he determined to attack first those who had separated from the main body, and were carrying on the campaign by themselves, under the command of Caius Cannicius and Castus; and he dispatched six thousand men, with orders to occupy a certain hill, and keep themselves concealed.  The men of Crassus endeavoured to escape notice by covering their helmets; but, being seen by two women, who were sacrificing for the enemy, they would have been in danger, if Crassus had not quickly appeared, and fought a battle, the most severely contested of all in this war, in which he destroyed twelve thousand three hundred men, of whom he found only two wounded in the back:  all the rest died in the ranks, fighting against the Romans.  After the defeat of this body, Spartacus retired to the mountains of Petilia,[38] followed by Quintius,[39] one of the generals of Crassus, and Scrofas, his quaestor, who hung close on his rear.  But, upon Spartacus facing about, the Romans were thrown into disorderly flight, and made their escape, after having with difficulty rescued their quaestor, who was wounded.  This success was the ruin of Spartacus, in consequence of the self-confidence which it infused into the slaves:  they would not now consent to avoid a battle, nor yet would they obey their commanders, whom they surrounded, with arms in their hands, on the march, and compelled to lead them back through Lucania against the Romans, wherein they did the very thing that Crassus desired; for it was reported that Pompeius was now approaching, and there were not a few who openly said that the victory in this war belonged to him; for he would fight as soon as he arrived, and put an end to the campaign.  While Crassus, therefore, who was eager to decide the affair by a battle, and to fix his camp near the enemy, was engaged in digging his trenches, the slaves came up to them and attacked the men who were at work.  As fresh men from both sides kept coming up to help their comrades, Spartacus, seeing that he must fight, arranged all his army in order of battle.  When his horse was brought to him, he drew his sword and