The spermatogenesis of Hydra. 
The spermatogonia: 
First generation 
Derivation 
Form 
Structure . 
Position 
Division in : 
Reduction in mel of mens 
in ordinary spermatogonia 
in marginal spermatogonia 
Second generation . 
The spermatocytes: 
First order 
Mitosis in . 
Second order 
The spermatid : 2 
Transformation of into the a en 
The spermatozoon 
Mitosis. Varying types af 
Type of in the spermary 
Type of outside the spermary 
Type of in interstitial and ectoderm wall 
Change in volume during mitosis 
Characterizes certain cells 
Summary, and comparison of types 
The centrosome . 
The mitotic figure 
Derivation of the fibres 
Nuclear wall . 
Chromosomes 
Chromomeres 
Reduction of Simeone: 
Reduction division . 
Nutrition of spermary during nenn 
The mesoderm 
The germ plasm . : - 
Relation of the bud to the poe : 
Hydra not a degenerate but a primitive foc 
