198 THE FCETUS. 



all these parts are formed behind the meatus auditorius, the ear 

 nevertheless seems to extend forwards during this whole period, 

 and to approach much nearer to the angles of the mouth and 

 eyes. 



505. The members very early reach the form of their perfect 

 state; in eight or nine weeks the fingers are all separate, or only 

 adhere to each other by a transparent gelatinous substance; their 

 three phalanges are distinguishable, and tend already to bend to- 

 wards the palmar surface of the hand; the last phalanx exhibits upon 

 its dorsal surface a spot which must be considered as the rudiment 

 of the nail; certain opaque lines indicate the situations to be occu- 

 pied by the bones of the metacarpus. The proportional length of 

 the arm and thigh, as respects the fore-arm and leg, is no longer ex- 

 traordinary. The germ of the shoulder and hip cannot be over- 

 looked. 



506. The coccygeal point is more completely concealed by the 

 pelvic members, and projects less than it does a fortnight later. 

 The anus ceases to exhibit the appearance of a blackish depressed 

 spot; at sixty days it forms a small conical projection, not perforated, 

 and of a more or less intense yellow color. The genital tuber- 

 cle continues to increase in length, and its base is surrounded by 

 a very thick cushion; at some distance from its extremity is seen a 

 circular groove which corresponds to the corona of the glans. 

 The channel along its inferior surface is in a great many embryos 

 entirely shut, but in some it is still prolonged in the form of a slit 

 to within one line of the anal tubercle. The development of the 

 perineum, of the pelvis, and hypogastrium, occasions the cord 

 which in the first period appeared to be inserted betwixt the roots 

 of the inferior extremities very near the coccyx, to remove to a 

 considerable distance from those parts, as it approaches nearer to 

 the centre of the abdominal protuberance. The circle of the um- 

 bilicus at last unites so intimately with the cord which passes 

 through it, that there is no longer any line of demarcation between 

 the teguments of the one and the membranous sheath of the other. 

 Then if, as until birth, the size of the belly appears to be enormous, 

 it must be attributed in part to the circumstance that the organs con- 

 tained in the pelvis on the one hand, and in the thorax on the other, 

 do not attain their perfect development until a very late period. 



507. Dimensions of the foetus at different stages of pregnancy. 

 As the embryo is curved forwards while it remains loose in the 

 centre of the ovum it seems to me that it ought always to be placed in 

 this situation when we go about to measure its length. How can we 

 otherwise obtain determinate results? If, during the first six weeks, 



