Explanation of the Figures on Plates I.-IX. 



All the Figures on Plates I.-IX. are given by means 

 of the Camera lucida. 



The enlargement of the Figures is as follows: 



ON PLATES I.-V. 



The enlargement of Figs. 1, 38, 39, 40, 41, 63, is **- 



,, ,, ,, 58, 59, is -. 



All the other Figures on Plates I.-V. are enlarged 140 times. 

 Wherever the figures are specially small, as for instance 7, 9, 

 48, 49, and wherever specially large, as for instance 50-53, refer- 

 ence must be had to individual distinctions of the embryos. 



ON PLATE VI. 



The enlargement of Figs. 64, 65 = -\ 6 -. 



Fig. 66 = *a4. 



Fig. 67 = if a. 



Figs. 68, 69, 70 = ^- 2 . 



ON PLATES VII.-IX. 



The enlargement of Figs. Ill and 151 is ^p. All the other 

 figures are enlarged -^^ times. 



I have not in the text given any proportions of in- 

 dividual parts, since they may be computed from the 

 drawings by means of compass and rule. 



166 



