The value of thromboplastic agents in the treatment of hemorrhage is questioned by many laboratory workers and by some is reported as being nil. There are so many things which influence the time of coagulation that reservation must be given in measuring the evidence offered to support their real value. Experimentally the withdrawal of 4 cc. of blood from a rabbit may decrease the coagulation time for several days. Suffice it to say that any coagulant derived either from blood or from tissue should not be introduced into the vein unless it is protein free as evidenced by the absence of any coagulation on boiling. The use of ovarian extract in hemophilia is strongly advocated by some and as strongly disapproved by others. The present evidence would indicate that it is worthy of a trial. However, the most reliable aid in hemophilias at the time of operation is small blood