MATURATION. 



33 



the corpus luteum of menstruation, or the false corpus luteum, although there 

 are no actual microscopic differences between the two. 



Point of rupture 



, 

 Connective tissue - X"" 1 "*', 



oiff9* 



Connective tissue 

 from theca 



Theca folliculi 



Remnant of corpus 

 haemorrhagicum 



Blood vessels 

 of theca 



FIG. 21. From section of human ovary, showing later stage of corpus luteum than Fig. 20. 



Kollmann's Atlas. 



PRACTICAL SUGGESTIONS. 



The reduction of chromosomes is beautifully illustrated in Ascaris megalocephala 

 (bivalens). This species of Nematode is parasitic in the intestine of the horse and can 

 usually be procured by a veterinarian. The oviducts are carefully removed and treated 

 as follows: 



Gilson's alcohol -acetic-sublimate mixture, 15 to 30 minutes. 



70% alcohol, with little tincture iodine, several changes, 24 hours. 



70% alcohol, indefinitely. 



Borax-carmin, 24 hours. 



i% HC1 in 70% alcohol, 24 hours. 



Absolute alcohol and glycerin, equal parts, 24 hours. 



Glycerin, indefinitely. 



Mounting for study is carried out as follows: Cut the oviduct into about six pieces of 



equal length, being careful to keep the pieces in order. Cut a small bit from one of the 



pieces, gently shake some of the ova into a small drop of glycerin on a slide and carefully 



apply a glass. Pressure on the cover-glass will crush the ova. Ova from all the pieces are 



