118 



OBSTETRIC A L PH YSIOL OQ Y 



years old ; but, as a rule, in the adult animal it is only represented by 

 a small and variable quantity of adipose tissue. 



The liver is extremely voluminous in the early period of embryonic 

 and fcBtal life, but decreases proportionately as gestation approaches 

 its close. In the foetus of a Lamb at the fifty-seventh day it has been 

 found equal to l-6th of the body in weight ; in Calves at mid-term and 

 birth to l-29th ; with the Foal at birth l-21st, and l-24:th in Lambs at 

 the same period. In the adult Horse it has been fomid to represent 

 l-75th of the total weight, and l-83rd in the Ox. 



The intestines, during foetal life, do not grow in length so as to attain 

 the proportionate dimensions they offer in adult life. In an Equine 

 foetus of eight or nine months, the small intestines measured about 15 

 feet, the caecum 6^^ inches, and the large intestines Sh feet, or a, 

 total of about 20 feet — about l-5th of their length in after-life. Shortly 

 after birth they acquire l-3rd the length to which they attain when 

 fully developed. The Calf at mid-term has only 1-lOth the length of 

 the adult intestine — being only sixteen times the length of the body, 

 instead of twenty times. The Lamb and Kid at birth have l-3rd of 

 their intestines complete — their length is seventeen to eighteen times 

 the length of the body, instead of twenty-seven times in adult life. 



The general proportions of the body, and especially those of the 

 skeleton, are not in foetal life what they are after birth. The bones 

 are, relatively to the other parts, more voluminous as a whole, and 

 notably at their extremities, than in the adult. The limbs in particu- 

 lar, and this more so in Solipeds and Euminants, have attained a length 

 which is not at all proportionate to that of these parts when their 

 growth is completed. And several bones of the limbs, such as the 

 radial, tibial, metacarpal, and metatarsal bones, are almost fully 

 developed in their dimensions at birth. The following interesting table 

 exhibits the comparative weight of the different bones in the Foal and 

 the adult Horse. 



The weight is given in grammes (15-432 troy grains) : 



SECTION v.— PHYSIOLOGICAL PHENOMENA IN THE FCETUS. 



With regard to the physiological phenomena which occur during 

 foetal life, we cannot presume to speak in detail in this place. It is, 

 however, interesting, and perhaps necessary, to allude briefly to several 

 of the most important, in order to complete this portion of our subject. 



