The semen of man and animals is delivered from the urethra in a liquid state but differs thereafter in its properties in three principal ways. In the guinea pig it becomes an elastic solid which is maintained in this condition both in vitro and in the vagina for many days. The semen of the dog remains liquid. The ejaculate of normal man solidifies but then liquefies in a few minutes at room temperature.The solidification of the semen of the guinea pig is due to the action of an enzyme, vesiculase (1, 2) derived from a special region of the prostate (3) on the proteins of the seminal vesicle. No experiments have been reported dealing with the solid-liquid phases of human semen or with the persistence of the liquid state of canine semen, matters with which the present paper is concerned.Our first observation was that a mixture of human semen with blood underwent coagulation but soon liquefied. Most of the present experiments deal with various phases of the effects of semen and its components on blood and its clotting constituents. MethodsHuman semen was obtained by manual ejaculation. Following liquefaction, it was centrifuged and the supernatant fluid used immediately for testing. Canine semen was obtained by pilocarpine stimulation following the prostatic isolation procedure of Huggins, Masina, Eichelberger, and Wharton (4); this fluid was passed through a Seitz filter to obtain a sterile filtrate free from cells.Fresh blood and citrated plasma were obtained from various species. The plasma was procured by centrifugalization of blood drawn into a solution of sodiumcitrate, 5 per cent, of which 1 co. was used for each 9 co. of blood; it was recalcified with a solution of CaC12, 1.5 per cent, of which 0.33 cc. was used for each cubic centimeter of plasma.Testing for lytic activity was carried out by mixing 1 cc. of blood or plasma with Icc. of semen or other fluid under examination, either undiluted or diluted to 1 cc. with saline; after mixing, the tubes were stoppered and placed in a water bath at 37°C. and

548EXCRETION AND LOCALIZATION OF ARSENIC^^ cells, which multiply only in the presence of as a chemotherapeutic agent. streptomycin. The frequency with which Conclusions. The isolation and cultural streptomycin-resistant variants and organisms characteristics of a streptomycin-resistant capable of utilizing streptomycin for growth organism capable of multiplying in aqueous have been described has limited its usefulness s o h tions of streptomycin has been described.

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36328 days. A portion of the large intestinal wall, freed of feces, and a portion of liver were analyzed for emetine. The analysis was adapted from the general method of Brodie ei a1.2 4 Stetten, D.

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