CHAP, ii.] PREGNANCY AND BIRTH. 389 



activities of the embryo, our knowledge is almost a blank. We 

 know scarcely anything about the various steps by which the 

 primary fundamental qualities of the living matter of the ovum 

 are differentiated into the complex phenomena which we have 

 attempted in this book to expound. We can hardly state more 

 than that while muscular contractility becomes early developed, 

 and the heart probably, as in the chick, beats even before the 

 blood-corpuscles are formed, movements of the foetus are in the 

 human subject first felt about the sixteenth week ; they probably 

 occur before but are not easily recognised, while from that 

 time onward they increase and subsequently become very marked. 

 They are often spoken of as reflex in character, and some 

 of them are undoubtedly of this nature. When the uterus of 

 a pregnant animal is prematurely opened, various reflex move- 

 ments of the foetus may be excited by appropriate stimulation, 

 different kinds of animals differing in this respect as they do 

 with regard to the powers of the new-born animals. Such reflex 

 movements may be witnessed before the placental circulation has 

 been interrupted, but they are increased if the foetus be made to 

 breathe. We have already referred to swallowing movements ; 

 and may add that an immature foetal animal may be made to bite 

 by introducing the finger into its mouth. Some of these normal 

 intra-uterine movements appear however to be not reflex but 

 automatic if not voluntary in nature. Movements of the limbs, 

 apparently automatic, have been observed in foetuses in which the 

 brain has not been developed. We may add that in the human 

 subject the occurrence of intra-uterine convulsions is fully ac- 

 knowledged. 



961. The digestive functions are naturally, in the absence 

 of all food from the alimentary canal, in abeyance. Though pep- 

 sin may be found in the gastric membrane at about the fourth 

 month, it is doubtful whether a truly peptic gastric juice is se- 

 creted during intra-uterine life ; trypsin appears in the pancreas 

 somewhat later, but an amylolytic ferment cannot be obtained 

 from that organ till after birth. The date however at which these 

 several ferments make their appearance in the embryo appears to 

 differ in different animals. The excretory functions of the liver 

 are developed early, and about the third month bile-pigment and 

 bile-salts find their way into the intestine. The quantity of bile 

 secreted during intra-uterine life accumulates in the intestine and 

 especially in the rectum, forming, together with material secreted 

 by the walls of the alimentary canal and some desquamated 

 epithelium, the so-called meconium. Human meconium is found 

 to contain about 20 p.c. of solids. These consist of a considerable 

 quantity of cholesterin (? p.c.), some fatty acids, bile salts with bile 

 pigments, both largely unaltered, and calcium and sodium salts ; 

 the ash is rather more than 1 p.c. Though bile contributes nor- 

 mally to form the meconium, it is not essential, for a considerable 



