648 DEVELOPMENT OF THE ALIMENTARY CANAL 



tine they are semifluid or gelatinous in consistency, of a light 

 yellowish or grayish-white color in the duodenum, becoming yellow, 

 reddish-brown and greenish-brown below. In the large intestine 

 they are of a dark greenish hue, and pasty in consistency ; and the 

 contents of this portion of the alimentary canal have received the 

 name of meconium, from their resemblance to inspissated poppy- 

 juice. The meconium contains a large quantity of fat, as well as 

 various insoluble substances, probably the residue of epithelial and 

 mucous accumulations. It does not contain, however, any trace of 

 the biliary substances (tauro-cholates and glyko-cholates) when care- 

 fully examined by Pettenkofer's test ; and cannot therefore properly 

 be regarded, as is sometimes incorrectly asserted, as resulting from 

 the accumulation of bile. In the contents of the small intestine, on 

 the contrary, traces of bile may be found, according to Lehmann, 1 

 so early as between the fifth and sixth months. We have also 

 found distinct traces of bile in the small intestine at birth, but it is 

 even then in extremely small quantity, and is sometimes altogether 

 absent. 



The meconium, therefore, and the intestinal contents generally, 

 are not composed principally, or even to any appreciable extent, of 

 the secretions of the liver. They appear rather to be produced by 

 the mucous membrane of the intestine itself. Even their yellowish 

 and greenish color does not depend on the presence of bile, since 

 the yellow color first shows itself, in very young foetuses, about 

 the middle of the small intestine, and not at its upper extremity. 

 The material which accumulates afterward appears to extend from 

 this point upward and downward, gradually filling the intestine, 

 and becoming, in the ileum and large intestine, darker and more 

 pasty as gestation advances. 



It is a singular fact, perhaps of some importance in this connec- 

 tion, that the amniotic fluid, during the latter half of fcetal life, 

 finds its way, in greater or less abundance, into the stomach, and 

 through that into the intestinal canal. Small cheesy-looking masses 

 may sometimes be found at birth in the fluid contained in the 

 stomach, which are seen on microscopic examination to be no other 

 than portions of the vernix caseosa exfoliated from the skin into 

 the amniotic cavity, and afterward swallowed. According to Kol- 

 liker, 2 the soft downy hairs of the foetus, exfoliated from the skin, 



' Physiological Chemistry, Philadelphia edition, vol. i. p. 532. 

 2 Gewebelehre. Leipzig, 1?52, p. 139. 



