LIST OF FIGURES. 



Fig. I. Formation of spermatozoa in Ascans megalocephala 



II. Formation of ova ,, ,, ,, 



III. Behaviour of idants during the development of germ-cells 



IV. Formation of spermatozoa in Pyrrhocoris 



V. Diagram of a double idant ,, ,, 



VI. Formation ,, ,, .. ,, 



VII. Wreath of four idants .... 



VIII. Maturation of parthenogenetic egg , 



IX. Germinal vesicle of parthenogenetic egg oi Artemia 



X. The two varieties of Cypris reptans, A and B. 



XI. Conjugation oi Paramaecititn ..... 



XII. Diagram of the conjugation oi Colpidhtnt 



PAGK 



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