The semen ejaculated by Rudra converted in the form of a white mountain. The constalations Krittikas etc. had transmitted the was fire semen at that white mountain made of Rudras semen.
रुद्रेण शुक्रमुत्सृष्टं तच्छ्वेत: पर्वतोऽभवत्। पावकस्येन्द्रियं श्वेते कृत्तिकाभिः कृतं नगे॥