PUBERTY AND MENSTRUATION 



433 



for the viscera fit snugly together, and that the few spaces there are 

 between them are filled with lymph. The plasma poured out with the 

 ovum serves undoubtedly to float the latter into the stream trending into 

 the tube, for else the peculiar nature of the follicle is unintelligible. 

 There is however, also a permanent anatomical connection between the 

 tube and the ovary by means of the ovarian fimbria, and it is likely that 

 it is by this channel that the ova usually pass, the other fimbrise being 

 present perhaps to pick up the stragglers from this straight and narrow 

 way. Sometimes the ovum becomes fertilized on or near the ovary and 

 fails to reach the safe channel of the tube, the fetus then developing as an 

 abdominal (ectopic) pregnancy. Maturation occurs either just before 

 or just after the follicle's rupture, and fertilization, while occurring 

 usually in the peripheral part of the tube, may take place at any time 

 after the rupture, even in the uterus. The relations of the two ovaries 

 as regards ovulation are unknown, but there is a likelihood that both 

 ovaries ovulate every month. 



FIG. 247 



Section through the Fallopian tuba. (Bates.) 



$1 The Corpus Luteum. When the follicle has burst and freed its ovum 

 its duties as a follicle are done. If we may trust, however, the recent 

 work of several men, and especially of Frankel, the follicle forthwith 

 takes on a new function, that of producing an internal secretion, which 

 stimulates the growth of the muscular parts of the sexual organs, and 

 perhaps of others (heart, for example?), to meet the demands of the 

 expected pregnancy. Aside from the experimental evidence for this, the 

 hollowness and the large size of the Graafian follicle in themselves are 

 additional testimony. These conditions apparently are not necessary 

 merely for the development of (and maturation of?) the ovum but rather 

 preparation for the corpus luteum. This glandular (?) organ is formed 

 according to von Baer substantially as follows: When the follicle bursts 

 open in ovulation to allow of the ovum's release, blood escapes into 

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