ANIMAL AND VEGETABLE 



119 



ANIMAL 



VEGETABLE 



ex 



Fig. 30. Fig. 31. 



Diagram of a cell. p, proto- Young pollen-grain of Lilium 

 plasm ; n, nucleus ; n 1 , nucleolus ; Martagon, showing, c, double con- 

 c, double centrosome ; ex, exo- trosphere ; n, resting nucleus ; 

 plasm. (After Schafer.) n\ nucleolus ; p 9 protoplasm. 



(After Guignard.) 



Fig. 32. 



Diagram showing a change in 

 the centrosomes and nucleus of a 

 cell in the process of mitotic divi- 

 sion. The nucleus is supposed to 

 have four chromosomes. (After 

 Schafer.) 



Fig. 34. 



Fertilisation of the ovum by the 

 spermatozoon (of a mammal). 

 (After Haeckel). 



Fig. 33. 



Germinating pollen-grain of Li- 

 lium Martagon with dividing nu- 

 cleus : the kinoplasmic spindle is 

 formed with a centrosphere at each 

 pole ; n is the nuclear disc formed 

 by the chromosomes. (After 

 Guignard.) 



Fig. 35. 



Oosphere, with spermatozoids. 

 (After Strasburger.) 



