156 



THE HUMAN EMBRYO. 



protrusion of the coils of the intestine into the ccelom of the umbilical cord is 

 about at its maximum. 



Embryos of Sixty-two Days, 30 mm. The present specimen (Fig. 107) came 

 with no data and its age is therefore estimated only. The head is still larger in 

 proportion to the body than in figure 106. The face shows the two lines which, as 

 seen in profile, mark the two ridges which run over the cheek, one alongside the 

 nose to the corner of the mouth, the other from the eye; these ridges are highly 

 characteristic of the ninth week, and traces of them not rarely persist in the adult 

 physiognomy. The limbs have grown considerably, the hands being lifted toward 

 the face; at the elbow there is a considerable bend; the toes are all free, and the 

 soles of the feet are turned each toward the other. The tail has disappeared as a 

 free appendage. The external genitalia are considerably developed; the clitoris-penis 

 projects some distance. 



Embryo of Sixty-four Days, 32 mm. A specimen came with the following his- 

 tory: "January 4, 1886, last flow began; March 13, 1886, abortion"; between these 

 two dates are sixty-eight days; but as the flow took place, conception probably 

 occurred after menstruation, therefore if we deduct four days, making the age 

 sixty-four days, we shall probably be not far wrong. The head has not yet as- 

 sumed its final angle with the body. On the other hand, the protuberance of the 



abdomen is much reduced, so that the body as a whole 

 has begun to have a more slender form than in earlier 

 stages. In this specimen the eyelids have not even begun 

 to meet; in another they have met, except just in the 

 center, where is still a loophole. 



Embryo of Seventy-five Days, 55 mm. We figure next 

 (Fig. 108). a fetus concerning which there are no data. 

 Comparison with embryos of two and three months leads 

 us to place it a little under half way between them. The 

 specimen has essentially the configuration of the young 

 child; but the head is very large and the body slender; the 

 position of the limbs is typical; the upper arm is bent 

 down, the forearm extends toward the chin; -the knee is 

 bent so as to throw the foot toward the median line; the soles 

 of the feet are placed obliquely facing one another; the anlages 

 of the nails can be recognized on both the fingers and toes. 



Embryos of the eleventh and twelfth weeks are very rarely obtained. I have 

 never had a normal one of this period with data to determine the age. 



Embryos of Three Months, 78 to 80 mm. In my experience there is no other 

 age at which abortion of normal embryos occurs so frequently as at three months, 

 and I possess a number of specimens of this age, which agree very . closely with 

 one another in size and form. The fetus drawn in figure 109 may be taken to 

 represent accurately the appearance of the human embryo at three months. The 





FIG. 1 08. HUMAN EMBRYO OF 

 55 MM. SEVENTY-FIVE 

 DAYS. NATURAL SIZE. 



