THE PELVIC CANAL 51 



of the transverse diameter is reached. Now the hand, with 

 its dorsal surface superiorly, is in a horizontal position. Next, 

 the thumb and little finger are extended, to ascertain approxi- 

 mately whether the pelvic inlet has the normal shape or not. 

 Thus one can investigate the pelvic dimensions by previously 

 measuring the distances between the extended thumb and 

 little finger or thumb and index finger respectively. Also, the 

 distance between the cotyloid cavities can thus be calculated, 

 and a stenosis recognized. 



Diameters estimated after this method are always smaller 

 than in reality. Especially the calculation of the vertical 

 pelvic diameter is made difficult on account of the recto- 

 vaginal excavation (excavatio recto -vaginalis). (St. Cyr and 

 Violet.) 



St. Cyr and Violet, employing Arloing's method, who 

 established the diameters of the equine pelvis, calculated the 

 diameter of the bovine pelvic inlet by distances measurable on 

 the external surface of the living animal. According to their 

 investigation, the height of the pelvic inlet (diameter sacro- 

 pubien) equals 0.180 times the height of the animal at the 

 withers, allowing an additional 5 to 15 mm. above and below. 

 My observations show that in the Holsteins this coefficient is 

 0.15, allowing even an additional 1.5 cm. 



The greatest pelvic width they calculated by multiplying 

 with 0.36 the distance between the external ilial angles. Here 

 also an additional 5 to 15 mm. is permissible. The circum- 

 ference of the pelvic inlet, according to these estimates, equals 

 3 44 times the average sum of the diameters ascertained for the 

 pelvic inlet. 



cd + cd — 2 



ab + 



2 



-X3.44 



In some animals examined by me I found the following 

 diameters (expressed in centimeters) : 



