j in ji 'to conquer' after a reduplication before the Desiderative affix san and in the liṭ (Perfect Tense).,
As जिगीषति, जिगाय ॥ Why in the Desiderative and Perfect only? Observe जेजीयते ॥ Though the root ज्या also assumes the form जि by vocalisation (VI. I. 16), (VI. I. 17) yet that जि is not to be taken here. That will form जिज्यतुः, जिज्युः ॥,