XX 



LIST OF FIGURES 



FIG. 



124. 



125. 



126. 



127. 



128. 



129. 



130. 



132. 

 134. 



135- 

 136. 



137- 

 138. 



139- 

 140. 



141. 



142. 



Diagrams of tetrad-formation in arthropods 



Germinal vesicles and tetrads 



Maturation in Auasa .... 



Maturation in Anasa .... 



Diagrams of reduction 



Maturation in Thalassema . 



Maturation in Thalassema and Zirphiza 



Maturation in Salamamira . 



The maturation-divisions in angiosperms 



Maturation in I. ilium .... 



Maturation in Liliiim .... 



Diagrams of reduction in the flowering plants 



Ovary of Canthocamptus .... 



Polar spindles without centrosomes 



Polar bodies in Actinophrys 



Polar bodies in Acti)wsphiErinm . 



Conjugation and reduction in Closteriiim 



First type of parthenogenetic maturation in Arlemia 



Second type of parthenogenetic maturation in Arlemia 



PAGE 



252 

 254 

 255 

 259 

 260 



261 

 262 

 264 

 266 

 268 

 270 



273 

 276 



278 



278 



279 



282 



28 -. 



CHAPTER VI 



143. Abnormalities in the fertilization of ^j<r^;-7,f 



144. G'xzni Qvnhxyo oi A scaris ...... 



145. Individuality ofchromosomes in Ascuris 



146. Independence of chromosomes in fertilization of Cyclops 



147. I lybrid fertilization of /^5frt'r;.y ..... 



148. Mitosis with intranuclear centrosome in Ascaris . 



149. Abnormal mitoses in Plemerocallis .... 



150. Centrosomes in Chctlopteriis and Cerehratiiliis 



151. Artificially produced asters and centrosomes in echinoderms 



152. Diagram of different types of centrosome and centrosphere 



153. P(j]ar mitoses in Diaiilula ....... 



154. Astral systems in Ufiio ....... 



155. Astral systems in Cerebratiilus and Thalassema . 



156. Structure of the aster in spermatogonium of salamander 



295 

 296 

 297 

 298 

 300 



305 

 306 



307 

 308 



310 



^12 



3^3 

 320 



326 



CHAPTER VII 



157. History of chromosomes in the germinal vesicle of sharks 



158. Nucleated and enucleated fragments oi Slylonychia 



159. Regeneration in Slenlor ...... 



160. Nucleated and enucleated fragments of . -////«'/'<? . 



161. Nucleated and enucleated fragments of plant-protoplasm 



162. Position of nuclei in plant-cells . 



163. Ovzxy o{ Forjictila .... 



164. Normal and dwarf larvse of sea-urchins 



165. Supernumerary centrosome in Ascaris 



166. Cleavage of dispermic egg of Toxopneiisles 



167. Centrosomes and cilia .... 



339 

 342 

 343 

 344 

 345 

 347 

 349 

 352 



355 

 356 

 357 



