Charles Eussell Bardeen and Warren Harmon Lewis 



Plate I. While the embr3'0 is similar in general differentiation to 

 Embryos CLXXV (Fig. 11) and CVI (Fig. 13), the development of 

 the digits of the hands and feet is further advanced. The flexion of the 

 forearm is also more marked. 



Fie:. 14. 



X about 3^ d. 



Fig. 15. 



Fig. 



Emhryo XLIII. 



14 represents Embryo XLIII; length, vertex-breach 16 mm., 

 neck-breach 14 mm.; age, about 6 weeks. The forearm and leg have 

 grown considerably beyond the stage shown in Figs. 11-13, but without 

 marked alteration in external form. 



Emhryo XXII. 

 Fig. 15 represents Embryo XXII; length, vertex-breach 20 mm., 

 neck-breach 18 mm.; age, about 7 weeks. A photograph is reproduced 

 on Plate I. The limbs have begun to resemble those of the adult. In 

 the hand the clefts between the digits are well marked. The forearm 

 and hand are somewhat pronated. The tips of the digits now reach 

 nearly to the ventral mid-line. In the hind-limb the foot still lies in 

 the same plane with the leg. The twist at the ankle which brings the 

 foot into adult position has not begun. The toes are fairly distinct.' 



' A number of embryos have been pictured wliich correspond essentially in external 

 form to those above described. The following list gives reference to the articles in 

 which several of these have been described and pictured. 

 To the His embryo R. Fig. 5, corresponds : 



Foil's 5.6 mm. embryo, Fig. 217, p. 386, Minot's Embryology. 

 To No. II, Fig. 6, corresponds : 



Keibel's embryo H. S., length 8 ram., Arch, fiir Anat. und Phys., 1891, Taf. TvIX, 

 Fig. 2. 



