SIGNS OF PREGNANCY 299 The Xenopus test9 or Hogl>en test may be used when a rapid diagnosis of early pregnancy is to be made. One c.cm. of prepared urine from the suspected case is injected into the lymph sac of a South African female toad (Xenopus Isevis), and extrusion of ova through the cloaca occurs within six to fifteen hours, if pregnancy is present. Male frogs and toads may be employed instead of female toads. One millilitre of the filtered first morning urine of the suspected case of preg- nancy is injected into the dorsal lymph sacs of two male toads. One to four hours later cloaca! samples of urine are withdrawn from both the toads by catheterization, and examined under the low power of a microscope. Spermatozoa in large numbers will be found floating on the glass slide, if pregnancy is present. It is advisable to collect the toads' urine at the time of injection and to check the absence of spermatozoa. Moha&ty and Pabrai10 recommend the injection of 10 millilitres of the patient's untreated urine into the dorsal lymph sacs of three healthy male toads (Bufo Melano- stictus Schneid), weighing from 50 to 70 grammes. A positive reaction is seen by the presence of spermatozoa in the toads' samples of urine after half to four hours. This test is simple, inexpensive, rapid and highly accurate. The same toads can be utilized every ten to twelve days with proper feeding. Signs of Pregnancy in the Dead.—In addition to some of the objective signs mentioned above, the diagnostic signs of pregnancy which are found in the dead body at the post-mortem examination are— 1. The presence of an ovum or foetus. 2. Uterine changes. 3. The corpus luteum. 1. The Presence of an Ovum or Foetus.—The presence of an impreg- nated ovum, foetus or placenta in the uterus after death is positive proof of pregnancy. In place of the ovum certain abnormal products of conception, such as sanguineous and vesicular moles, may sometimes be present. These moles develop so rapidly that the uterus is usually larger than at the corresponding period of normal pregnancy, but more frequently it is not enlarged beyond its size at the fifth or sixth month of gestation. 2. Uterine Changes.—As a result of pregnancy the uterus is thickened, and increases in size, both in its length and width. The length increases from one and-a-half inches to twelve inches, and the width from one and- a-half to about nine inches. Its weight at the full term of pregnancy is twenty-eight ounces or more. The nulliparous uterus weighs about an ounce, and that of the woman who has borne children weighs about an ounce and a half. The uterus also increases very much in its capacity, being five hundred or more cubic inches at its full development. The marks of the attachment of the placenta are also noticed. 3. The Corpus Luteum.—The corpus luteum is a cicatrix formed in the ovary after the escape of ova from the bursting of a Graafian follicle at the menstrual period. This corpus luteum develops in size for the first five or six days after the rupture of the follicle, remains quiescent for a few days more and then undergoes rapid absorption. In the event of pregnancy the corpus luteum continues to develop, and attains the largest size about the fourth month, forming a firm projection on the surface of the ovary. It ti^e^ undergoes a slow retrogressive change, although it is usually well mi^Slfe at the time of delivery, and may be evident for one or two months 1 r" v&'K-!^, 'M 9. Edward R. Elkan, Brit Med. Jour., Dec. 17, 1928, p. 1,253; F. Med. Journ April 15, 1939, p. 766. 10. Ind. Med. Gaz., Feb. 1950, p. 43.