126 OBSTETEICAL PHYSIOLOGY. 



peculiarities ; though between 38 and 45 kilogrammes may be accepted 

 as the average weight. 



With regard to the Bovine species, Tisserant has stated that Calves 

 weigh at birth from -jV^h to -^^th. of the weight of the Cow ; whereas 

 Eiedesel gives it as yV^h. Magne mentions that Calves vary between 

 20, 25, 45, and 50 kilogrammes. Saint-Cyr alludes to the observa- 

 tions made at the Agricultural School of Saulsie, France, where Cows 

 ■of the Ayrshire breed were chiefly kept. The animals were main- 

 tained in good condition all the year round, and though they were 

 only middle-sized, their weight varied between 400 and 650 kilo- 

 grammes. The Cows were regularly weighed, as were the Calves 

 immediately after birth, and the register for 1868 gave the following 

 results. The weight varied from 31 to 55 kilogrammes — the average 

 being 32^ kilogrammes. The males were a little heavier than the 

 females. In twenty-eight instances, the average weight of the Calf 

 compared with that of the Cow was as 2 to 31. 



The average weight of one hundred Lambs weighed at the Alfort pens, 

 is given by Magne as about 4 kilogrammes for both sexes. The males 

 ■were heaviest. 



For the Goat, Colin gives the weight of twins in two instances. In 

 the first, one twin weighed 3"530, and the other 3"585 kilogrammes — 

 together 7'215 kilogrammes ; in the second instance, one twin weighed 

 2-6830, and the other 2-680 kilogrammes — the weight of the two being 

 ■5-310 kilogrammes. 



Dimensions. 



With regard to dimensions, Saint-Cyr justly regrets the paucity of 

 observations which have been made on this important point. It is of 

 course well known that, in a general way, the fcetus is larger than the 

 pelvic opening through which it has to pass at birth, but we have to 

 ascertain how much larger it is than that canal, and what is the 

 -amount of reduction in volume to which it has to submit in passing the 

 outlet of the pelvis. Eainard merely states that some measurements 

 he had made gave the diameter of the thorax of Calves, from withers 

 to sternum (vertical) as from 10\ to 11 inches; and the diameter from 

 side to side (transversal) as 6^ to 7 inches. Saint-Cyr, anxious to 

 arrive at some definite conclusion in the matter, in order the better to 

 understand the mechanism of natural parturition, as well as to gain a 

 knowledge of how to surmount the difficulties of protracted labour, 

 undertook some researches in this direction. His object was to ascer- 

 tain the depth and width of the chest, and width of croup of the fcetus, 

 these being the dimensions which it is most important to compare with 

 the different diameters of the pelvis of the mother, so as to understand 

 how the former may accommodate themselves to the latter. He gives 

 the name of stcrno-dorsal line to the vertical measurement taken from 

 the summit of the highest dorsal spines to the sternum, and hiscapulo- 

 liuineral line to the distance measured from one scapulo-humeral articu- 

 lation to the other ; while the bicoxo-fcmoral line is the measurement 

 •of the croup from one coxo-femoral articulation to the other. From the 

 measurements in the Horse species, we find that a Mare measuring a 

 trifle over fifteen hands in height, and whose pelvis was nearly nine- 

 teen inches in width, brought forth a Foal weighing slightly less than 

 thirty pounds, and whose sterno-dorsal measurement was nearly twelve 

 inches, biscapulo-humeral line 7| inches, and bicoxo-femoral line nearly 



