SEXUAL ACTIVITY OF MALE RABBITS 475 
TABLE 2—Continued 
| INTERVAL | | 
DATE SINCE LAST 1st 5TH 10TH 157TH 20TH 
SERVICE 
Male 4 
1916 
6-27 10 230,000 50,000 
6-29 2 3,000 
7-8 9 191,400 117,500 
9-30 8 8,330 
10- 1 1 
1l- 9 24 13,000 5,000 1,300 
1917 
1-10 20 216,000 3 
1-19 9 107 
6-14 30 13,000 
Male 5 
6-15 115,000 35,000 3,000 500 
7-13 28 1,360 1,680 
Meansh ao: 5: ieee Pyle bse 104,578 34,886 14,692 4,155 3,492 
Standard deviations 
Olmmeans shes 15,318 6,991 3,784 1,840 1,458 
Standard deviations 
of difference of 
TNC AN Sees paceoien eras 16,836 7,949 4,206 2,346 
mass of semen recovered was placed into a weighed dish. The 
weight of semen present was multiplied by 9 and this volume 
of diluent (Ringer’s isotonic solution) was added. In this 
shape the specimen was used for study of live sperm. To 1 
ec. of the fluid prepared was added 1.5 cc. of a 4 per cent Na,CO; 
solution (the latter mixed with a small amount of saturated 
alcoholic methylene blue). This gave (on the assumption of 1.0 
as specific gravity of semen) a dilution of 25 times which was 
found to be most satisfactory for ‘normal’ semen. The Na,CO; 
broke up the agglutinated masses and the stain made counting 
easy when a drop of the fluid prepared thus was placed in the 
ruled counting chamber of a haemacytometer. We did not 
determine the actual specific gravity of rabbit semen. Lode 
made some determinations of this kind on dog and man; for the 
