^38 Erste Sektion: Cytologie und Protozoenkunde. Erste Sitzung. 



wise arises, is probably due to the limitations of the human mind 

 itself. Being only a part of a larger whole, it strives in vain to 

 explain the whole in terms of a part, such as a molecule, an atom, 

 or a biophore. 



Explanation of Plates. 



Plate Ia. 



Fig. i. Amoeba verrucosa. 



Fig. 2. Amoeba villosa. 



Fig. 3. Arcella discoides. 



Fig. 19. Ovarian Egg of very y oung Limulus, showing vitelline body, archo- 

 plasm and centrosome. 



Fig. 33. Diagram showing similarity in radial and concentric striations 

 of different cells. a) Ideal representation of what appears in b) the egg of Limulus, 

 in c) leucocyti, d) Ascaris, e) Clemmys. 



Plate Ib. 



Fig. 4. A Walking cell with two posterior, forked cilia, a ciliated groove 

 where food is taken in and several long cilia used more for Walking than for 

 swimming. 



Fertilized egg of Ascaris, showing polar body and aster and centro- 



First two cleavage cells of Ascaris, showing asters and centrosome. 

 Testis cells of Necturus showing aster and centrosome in resting 



Testis cells of Necturus showing asters and nucleus in Karyokinesis. 

 Ovarian egg of Limulus showing aster and centrosome, similar to 

 that of the fertilized egg of Ascaris. 



Fig. 21. Multipolar nerves cells showing fibrils, and their convergence in a 

 body resembling centrosome being in a notch of the nucleus. 



Fig. 22. Ovarian egg of Limulus showing vitelline body as a centrosome 

 and aster with concentric zones resembling those seen in the diving testis cells 

 ef Necturus, Figs. 17 and 18. 



Fig. 23. Ovarian egg of Limulus, gold chloride preparation, showing a more 

 distinct limitation of the concentric zones. 



Fig. 24. Ovarian egg of Limulus, showing vitelline body with astral rays. 



Fig. 26. Ovarian egg of the Spider, showing yolk nucleus resembling that 

 of Limulus, Fig. 25. 



Fig. 27. Small ovarian egg of the frog, showing a body in the cytoplasm 

 resembling a yolk nucleus or vitelline body. 



Fig. 28. Ovarian egg of the goose fish, showing at one pole of the nucleus, 

 a sphere with central granules and archoplasm extending part way around the 

 nucleus. 



Fig. 30. Ovarian egg of the crayfish, showing an indented germinal vesicle, 

 with modified protoplasm at the indented pole, in which a round vesicle appears, 

 the whole resembling archoplasm. 



Fig. 



15- 



some. 





Fig. 



16. 



Fig. 



17 



stage. 





Fig. 



18. 



Fig. 



20. 



