12 CARL GOTTFRIED HARTMAN 



nancy; recovery perfect. March 2, all external indications of pseudo- 

 pregnanc}^ disappeared. March 14, approaching ovulation indicated. 

 March 19, 2 p.m., left uterus removed and 20 eggs found. Animal was 

 killed at 8 p.m. and 17 eggs recovered from the right uterus. Eggs 

 varied in size and were in different stages of disintegration ; but the 

 case is here cited because one egg showed a '4-celled' stage, abnormal 

 as I am convinced, but comparable ill a way with the 4-celled stage of 

 the opossum as figured by Selenka and with the normal 4-celled egg 

 of Dasyurus. 



No. 117. February 13, the female having shown external signs of 

 ovulation, the left ovary and uterus were removed. 20 degenerate 

 eggs were found. By March 2 all external signs of pseudopregnancy 

 had disappeared. March 17, the sexual period being again indicated, 

 animal was killed and 43 eggs, small in size, were removed from remain- 

 ing uterus. The eggs included the following stages : twelve unsegmented 

 (several of these showed signs of beginning disintegration); two 2-celled; 

 two 4-celled (2 of these were apparently abnormal) ; one 5-celled ; two 

 6-celled; two 8-celled (one of these had seven cells in mitosis); two 

 13-celled; one 14-celled; one 15-celled; three 16-celled. 



No. 144. February 20, signs of pseudopregnancy. March 16, signs 

 of second (or third?) sexual period approaching. March 20 killed. 

 11 eggs removed from one uterus only and over-fixed in Carnoy's 

 fluid: one 12-celled stage, other eggs are young blastocysts like those 

 of Nos. 50, 82, and 88, or somewhat more advanced. 



3) Securing the eggs. On opening the body cavity of the female 

 the ovary w^as first examined, from the condition of which the 

 time that has elapsed since the discharge of the eggs may be 

 roughly estimated. Prominent blood-shot stigmata indicate re- 

 cent ovulation; a smooth surface with deep-seated dingy-yellow 

 corpora shows that ovulation was not recent. If in the latter 

 condition the uterus lacks fullness and turgidity, old degenerate 

 eggs are likely to be found. 



To secure the eggs the uterus is placed in a shallow vessel 

 containing Ringer's solution at 40° C. and the muscular w^all is 

 slit longitudinally. The intrauterine pressure at once forces out 

 the enormously swollen mucosa, which is richly supplied with 

 blood vessels and convoluted uterine glands. The uterine mucosa 

 is next gently pulled apart with two pairs of forceps, exposing 

 the lumen of the organ, and in the folds of the mucosa the eggs 

 may easily be seen with the aid of the binocular microscope, 

 and picked out with a pipette. Old, encrusted eggs can easily 

 be seen with the naked eye. Blastocysts of about 0.8 mm. 



