LIST OF ILLUSTRATIONS. 



FIG. 

 I. 



2. 



3- 

 4- 

 S- 

 6. 



7- 



II. 



12. 



13- 



14. 



15- 



16. 



17- 

 18. 



19- 

 20. 

 21. 



23- 

 24. 

 25. 

 26. 



PAGE 



Diagrammatic expression of classification in a genealogical tree, 1 1 



Structure of the cell. (Carnoy), .... 44 



Fertilised ovum oi Ascaris. (BovERl), ... 44 



Diagram of cell division. (Boveri), ... 45 



Karyokinesis. (Flemming), .... 47 



Diagrammatic expression of alternation of generations, . 55 



Diagram of ovum, showing diffuse yolk granules, . . 57 



Forms of spermatozoa, ..... 5^ 

 Diagram of maturation and fertilisation. (Geddes and 



Thomson), ...... 59 



Spermatogenesis and polar bodies. (Hertwig and 



Weismann), ...... 61 



Fertilisation in Ascaris iiiegalocephala. (BovERl), . . 62 



Modes of segmentation, ..... 64 



Life history of a coral, j1/tf«ffAeKM 2)a;-m«'«?V. (H.-ECKEL), 65 



Embryos (1) of bird ; (2) of man. (His). ... 69 



Gradual transitions between Pahidiiia Neiunayri and Pahc- 



dina ffcernesi. (Neumayr), .... 77 



Life history of Amaba^ ..... 87 



End-to-end union of Gregarines. (Frenzel), . . 88 



Life history of Gregarina. (BiJTSCHLl), ... 89 



Life history of yI/o?2(7(yj-/M. (Butschli), ... 90 



Paraincecium. (BuTSCHU), .... 91 

 Conjugation of Paraniaciuiu aurelia — four stages. 



(Madras), ...... 92 



Diagrammatic expression of process of conjugation in Para- 



maciitm aurelia. (Maupas), .... 93 



Vorticella. (Butschli), ..... 95 



Volvox globator. (CoHN), . , . . . 96 



V)\2L^X'ixa <ii Protomyxa aiiraiitiaca. (H/ECKEL), . . 99 



Formation of shell in a simple Foraminifer. (Dreyek), . 100 



