60 OBSTETRICAL PHYSIOLOGV. 



In other animals this ejection sometimes consists of a viscid, red- 

 tinted, or sangtiinolent fluid. In all it has a special and powerful odour, 

 which attracts the males, and enables them to distinguish between the 

 females which are in " rut " or " heat," and those which are not, as well 

 as exciting in them the most ardent amatory desires. 



The uterine mucous membrane is also very congested, and there is 

 poured out on its surface a fluid containing epithelial debris, mucus 

 corpuscles and blood globules. 



The existence in the lower animals of what is analogous to the 

 menstrual discharge in the human female, has frequently been denied, 

 but without any reason or proof. A discharge of blood from the sexual 

 organs of woman announces the advent of puberty ; and its coincidence 

 with the maturity and escape of the ovarian o^nile, as well as its 

 periodical appearance until the termination of fertility, establishes 

 between this phenomenon and the "heat " or " rut" (cestrum) of animals 

 a very close analogy. And this analogy is rendered complete by the 

 fact that animals also at this period have more or less evident sanguine 

 emissions. Kahleis, Fuchs, Spinola, Numann, and others have observed 

 this in the Cow, and have also noted that the discharge occurs regularly 

 at intervals of nineteen or twenty days, when the animal is not giving 

 milk or in calf. The haemorrhagic flow appears two or three days after 

 the commencement of " rutting," and when this is most intense. The 

 amount of blood does not exceed one or two ounces, and the coagulated 

 clot remains in the vagina until it is expelled with the urine. There 

 can be no doubt as to its source. If, at the moment when traces of it 

 are perceived externally, the Cow is killed and the inner surface 

 of the uterus examined, blood will be seen exuding from the cotyledons. 

 And this phenomenon has been proved to extend bej'ond the Bovine 

 species, for it has been witnessed in the Mare, Bitch, Cat, Eabbit, etc.; 

 and in the red-coloured mucus of the vagina and uterus, multitudes of 

 blood-corpuscles have been found. 



Not only is the existence of a menstrual discharge in animals a well- 

 ascertained fact, but the ill effects of its retention in cases of uterine 

 obstruction or occluded vagina, have been recorded as occurring in both 

 the Bovine and Equine species. 



The cause of menstruation or periodical discharges of blood in female 

 animals, has received a satisfactory explanation from the researches of 

 Eouget, who has established the fact that the utero-ovarian artery, on 

 arriving at the body of the uterus, near the Fallopian tube, divides into 

 curs^ed or spiral bouquets of vessels which open into veins, like the 

 helicine arteries of the male cavernous sinus. Along the inferior border 

 of the ovarj", this artery forms a series of branches that wind and twist 

 exactly like the arterial ramifications at the root of the corpus cavern- 

 osuin, penetrating the stroma of the ovary, and giving rise to spiral con- 

 volutions. The venous system composes the uterine sinuses — contorted 

 venous canals not unfrequently spiral, like the arteries. 



The uterus is, therefore, an erectile organ like the penis, and its 

 erection is connected with the periodic haemorrhage from its inner 

 surface. The venous sinuses in the meshes of the muscular tissue, 

 crossing each other at the hilus of the ovary, are partially compressed, and 



twent3'-four years of age, which every three weeks had a sanguineous emission from the 

 vulva ; this discharge ceased towards the middle of pregnancy, but returned after 

 parturition. I have frequently witnessed the periodic discharge from Mares either 

 streaked with blood, or blood-tinted. 



