LUTEINISING HORMONE IS A GONADOTROPHIN SECRETED BY ANT. PITUTARY TOGATHER WITH FOLLICLE STIMULATING HORMONE .L.H. IN WOMEN IN THE MID NCYCLE CAUSES RUPTURE OF THE FOLLICLE WITH OVULATION AND CONVERTS THE FOLLICLE INTO THE CORPUS LUTEUM WHICH SECRETES PROGESTERONE. IN MEN L.H. STIMULATES THE INTERSTITIAL CELLS OF TESTIS TO SECRETE TESTOSTERONE, WHICH IS IN TERN HAS A DIRECT EFFECT ON SEMINIFEROUS TUBULES.