194 THE FGETUS. 



which modern writers account for the formation of simple or double 

 hare-lip, which according to them, should never be met with exactly 

 in the middle of the lip; finally, still improving upon these divisions 

 which are already too numerous, it has recently been asserted that 

 the upper lip is developed from four separate points. I think I may 

 venture to affirm, that such ideas could only have arisen from obser- 

 vations not attentively made, or too rarely repeated. In the course 

 of the period I am now examining, the lower lip begins to be per- 

 ceptible; the chin causes the middle of it to project forwards; but 

 its loose edge, which is pretty thin, is not interrupted by any slit, 

 and represents a very regular semicircle; it is longer, and has a 

 deeper curve than the other; but in embryos of six weeks, and in 

 some a little above twenty days old, I have found the edges of both 

 lips perfectly formed, and without any division whatever. 



494. The nose. It is incorrect to say that the organ of smell 

 cannot be recognised until towards the sixth or eighth week. At 

 thirty days it is often in our power to distinguish its anterior open- 

 ings, which are round, situated immediately above the mouth, look 

 directly forw ards, and resemble two blackish spots. However, 

 neither the nasal protuberance properly so called, nor the naso- 

 palatine vault exist as yet. It is true, nevertheless, that, in several 

 embryos of from five to seven weeks, the orifices of the nose were 

 not very evident to me, while a very decided eminence already occu- 

 pied its place. 



495. The eyes. The organs of vision appear at the same time 

 with the mouth, if not earlier. I have distinguished them in em- 

 bryos not exceeding four lines in length, and they are never sought 

 for in vain in the course of the fourth week. At this period its 

 structure is surprisingly simple, if compared to what it must become 

 at a later period. Without lids, canlhi, or lacrymal apparatus, re- 

 sembling a circular disc half a line in diameter, and slightly convex, 

 the visual bulb is separated from the surface only by a slight, super- 

 ficial and very narrow groove, which can only be found by searching 

 for it with a needle. Two spots seem to constitute it entirely: one 

 of a yellowish white composes the centre; the other, of a black 

 color, exhibits the appearance of a circle, on the one hand enclosing 

 the former, and on the other continuous with the integuments. The 

 central spot is at first much larger than the black circle that sur- 

 rounds it, but in general the latter seems to me to exceed the former 

 in size towards the end of the sixth week. The whole indubitably 

 represents the sclerotica, and the transparent cornea, which is still 

 comjiletely opaque, and se^ms not to differ from the nails, except 

 in regard to color. It might in fact be called a portion of skin or 



