MERISTIC PHENOMENA 



39 



the outward symptoms of division, but we have no surmise as 

 to the nature of the process by which the division is begun or 

 accomplished. I know nothing which to a man well f rained in 

 scientific knowledge and method brings so vivid a realisation 



E 



FIG. 2. Jaws of Skates (Rhinoptera) showing meristic variation. (For a detailed 

 discussion see Materials for the Sttidy of Variation, p. 259.) 



of our ignorance of the nature of life as the mystery of cell- 

 division. What is a living thing? The best answer in few words 

 that I know is one which my old teacher, Michael Foster, used 

 to give in his lectures introductory to biology. "A living thing 



