720 DEVELOPMENT OF THE COMMON PHALWGER, 



covered the eye — a minute slip being still left between the 

 eyelids. 



Embryo H (li-8 mm ). Plate xxiii., fig. 7. 



This embryo is a very good example of the newly born con- 

 dition. I have in ray jDOssession six embr3ros in which part of the 

 umbilical cord is still attached, and all ot" which may be regarded 

 as newly born. Of these the greatest lengths are 13 mm., ISS 

 mm., 14-5 mm., 14-8 mm., L5-2 mm., and 15-4 mm. As these 

 embryos have all been similarly preserved, it will be seen that 

 there is some slight variation in the exact size at birth, but that 

 the average size is a little over 14 mm. Even at this ^-ery early 

 stage when the little embryo is removed from the teat it makes 

 clawing movements with its fore limbs as if endeavouring to pull 

 itself on to the teat again; and as a result of this the fore limbs 

 in the preserved sjDecimens are found in very various attitudes- 

 The palms are usually turned more or less downwards and 

 inwards, and the limbs project forwards. In one specimen, how- 

 ever, the limbs are raised, and the back of the right hand almost 

 touches the side of the head. The claws are very sharp and 

 fairly long. In most specimens the head is well raised — its axis 

 being at right angles to that of the body. The epitrichial layer 

 is so thick that the eye can only with difticult}^ be made out, 

 while the ear is completely covered over and only indicated by 

 the folded pinna causing a little projection. The posterior 

 portion of the embroyo is usually curved forwards so that the 

 hind limbs are made to point forwards and somewhat upwards. 

 The digits of the posterior limb are all well marked out and 

 partly separated — the 4th and 5th digits being distinctly the larger. 

 Tiie tail is comparatively short. Between the two posterior 

 limbs is found a projection which looks like a well marked penis. 

 But not only at this stage, but for long after, not the slightest 

 difference can be seen, at least externally, between the penis of 

 the male and the clitoris of the female. (Note the well marked 

 clitoris in the female embryos shown in figs. 11 and 12). There 

 is as yet no trace of the pouch or scrotum externally. 



