DISEASES OF THE GENERATIVE ORGANS. 



DESCRIPTION OF PLATES. 



Plate XII: 



Fetus with its membranes at mid term. The uterus is opened on the left side. 

 In the uterus the fetus is surrounded by several membranes, which are 

 known as the amnion, or inner layer, the allantois, or central layer, and the 

 chorion, or outer layer. The amnion, or inner membrane, is nearest the 

 fetus, and forms a closed sac around it, filled with a fluid known as liquor 

 amnii, in which the fetus floats. 



The allantois is the central membrane, and is composed of two layers which 

 form a closed sac in connection with the urachus, or the tube which extends 

 from the fetal bladder through the umbilical cord. The one layer of the 

 allantois is spread over the outer surface of the amnion and the other 

 over the inner surface of chorion. The allantois also contains a fluid which 

 is known as the allantoid liquid. 



The chorion is the outer envelope or membrane of the fetus, completely inclos- 

 ing the fetus with its other membranes. On the outer surface of this 

 membrane are found the fetal placentulae, or cotyledons, which, through 

 their attachment to the maternal cotyledons, furnish the fetus with the 

 means of sustaining life. The relation of the fetal and maternal cotyle- 

 dons to each other is illustrated on the following plate. 

 Plate XIII: 



Fig. 1. Uterus of the cow during pregnancy, laid open to show the cotyledons 

 (rf) on the internal surface of uterus (c). The ovary (a) is shown cut 

 across, and the two halves laid open to show the position of the discharged" 

 ovum at a'. 



Fig. 2. Illustrates the relation of the fetal and maternal parts of a cotyledon. 

 A portion of the uterus (A) is shown with the maternal cotyledon (BB) 

 attached to it. The fetal portion (D) consists of a mass of very minute 

 hairlike processes on the chorion (E) , which fit into corresponding depres- 

 sions or pits of the maternal portion. Each portion is abundantly supplied 

 with blood vessels, so that a ready interchange of nutritive fluid may take 

 place between mother and fetu^. 

 Plate XTV: 



Fig. 1. Taken from Fiirstenberg-Leisering, Anatomie und Physiologie des 

 Rindes. Fetal calf with a portion of the wall of the abdominal cavity of 

 the right side and the stomach and intestines removed to illustrate the 

 nature of the umbilical or navel cord. It consists of a tube (1-1') into 

 which pass the two umbilical arteries (3) carrying blood to the placenta 

 in the uterus or womb and the umbilical vein (4) bringing the blood back 

 and carrying it into the liver. The cord also contains the urachus (2'), 

 which carries urine from the bladder (2) through the cord. These vessels 

 are all obliterated at birth. 5, liver; 5', lobe of same, known as the lobus 

 Spiegelii; 5", gall bladder; 6, right kidney: 6', left kidney; 6", ureters, or 

 the tubes conducting the urine from the kidneys to the bladder; 7, rectum, 

 where it has been severed in removing the intestines; 8, uterus of the 

 fetus, cut off at the anterior extremity; 9, aorta; 10, posterior vena cava. 

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