NEW CONCEPTIONS IN SCIENCE 



If a normal animal be cut in twain, in the middle, 

 and a new mouth grown at the lower end of the 

 upper half and then the animal laid on its side, 

 both ends take in food. If fed in succession, one 

 mouth would reject the food it had just swallowed 

 when the other mouth took food. 



Many other experiments, curious and fanciful, 

 disconcerting too, followed. Mere contact with 

 a solid substance could turn one organ into an- 

 other. Organs were grown in the most absurd 

 places, others were transplanted. This work was, 

 of course, taken up by hundreds of other investi- 

 gators all over the world, and as a purely fantastic 

 instance, Ribbert has recently shown that a mam- 

 mary gland transplanted to the ear of a guinea-pig 

 would begin to secrete normally when a litter was 

 born. 



All this seemed to show that there is no com- 

 plex structure in the germ-cells from which these 

 lower forms spring, but that their varying shapes 

 are simply a reaction between a specific kind of 

 protoplasm and the physical forces of light, heat, 

 contact, and chemism, which mould it this way or 

 that. It is a fascinating field, and many would 

 have counted it sufficient for a life work. Not so 

 this innovating spirit. 



A new time was stirring in the stagnant prov- 

 inces of chemistry. Under the lead of van't Hoff, 



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