THE HORMONES IN HUMAN REPRODUCTION 



As Hartman calculates, it would require about 2,000,000 eggs 

 to fill an average sewing thimble. 



We know fairly well the appearance and size of the human 

 ovum while it is still in the growing follicle of the ovary, but 

 our information about the fully mature egg (that is, during 

 the last hours before it leaves the ovary, and while it is in the 

 oviduct) is derived from a mere handful of specimens, about 

 ten or twelve in all, that various investigators have been able 

 to obtain. The Rhesus monkey has yielded to science a some- 

 what larger treasure of eggs. If anyone wants monkey eggs 

 in market lots, they might be furnished for two or three thou- 

 sand dollars a dozen. To compensate for this scarcity of 

 primate eggs, those of the laboratory animals are fairly easy 

 to collect, and the domestic pig is a prime source. I have 

 myself handled 2,500 or more sow's eggs and used to dem- 

 onstrate them annually to my medical students. Any high- 

 school biology teacher who lives near a slaughterhouse, if 

 he will learn the tricks of finding and handling them, can show 

 his boys and girls this striking evidence of the unity of living 

 things. 



The clear outer membrane of the mammalian egg is tough, 

 like a very stiff gelatine solution, stifFer yet than a house- 

 wife would serve for dessert. I have often pushed the eggs 

 of rabbits and pigs over the bottom of a dish of salt solution, 

 using a coarse needle which under the microscope looked like 

 a poker pushing a grape. The tough egg membrane easily 



Plate VII. Structure of the ovary. A, diagram of a section through ovary, 

 illustrating the structures described in the text. From an article by the author, 

 in Physiological Reviews, by permission of the editor. B, pliotograph of small 

 part of a microscopical section of a monkey's ovary. The letter c indicates the 

 cortex of the ovary, containing egg cells not yet surrounded by follicles, o.f., an 

 atretic (degenerating) follicle. Photograph magnified 50 diameters. C, photo- 

 graph oif section of ripe egg of Rhesus monkey, in its hillock inside a large 

 follicle (Corner collection, no. 100). Magnified 100 diameters. D, photograph of 

 living human egg, recovered from Fallopian tube at operation. Preparation by 

 Warren H. Lewis (Carnegie collection, no. 6289). Magnified 200 times. 



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