EXPLANATION OF FIGURES. 



319 



Fig. 98. 



FIGS. 95-98. Transverse sections through embryo Chick : Fig. 95, the 

 second day of incubation ; Fig. 96, the third ; Fig. 97, the fourth ; and Fig. 

 98, the fifth. Figure* 95-97 are after Kolliker (magnified about 100 times) ; 

 Fig. 98, after Remak (magnified about 20 times). 



h, horn-plate ; mr, spinal tube ; ung, primitive kidney duct ; un, pri- 

 mitive kidney vesicle ; lip, skin-fibrons layer ; m = mu = mp, muscle- 

 plate ; iiu; primitive vertebral plate (wk, membranous formation of the 

 vertebral body ; u-1), of the vertebral arch ; it?y, of the rib, or transverse 

 apophysis) ; uich f primitive vertebral cavity ; cli, spinal axis, or noto- 

 chord , sh, notochord-sheath ; Ih, ventral wall{ g, posterior; v, anterior 

 nerve roots of the spinal marrow ; a = a/ = am, amnion-fold ; p, body- 

 cavity, or crelom ; df, intestinal-fibrous layer; ao, primitive aortas; sa, 

 secondary aorta ; vc, principal veins ; d =. dd, intestinal-glandular layer ; 

 dr, intestinal groove. In Fig. 95, the greater part of the ngnt half of the 

 cross-section is omitted, and in Fig. 96 the greater part of the left half. 

 Only a small part of the wall of the yelk-sac, the remnant of the germ- 

 vesicle, which lies below, is shown. 



especially to those who are not at all familiar with the 



