Illustrations xiii 



FACE 



SMOOTH NEWTS NEARLY MATURED FOR TERRESTRIAL LIFE, JUST BEFORE 



LEAVING THE WATER TO BECOME LAND ANIMALS .... 692 



SMOOTH NEWT MOULTING ITS SKIN AFTER RETURNING TO THE WATER 

 FOR THE BREEDING SEASON ........ 693 



MALE AND FEMALE SMOOTH NEWTS AT THE HEIGHT OF THE BREEDING 

 SEASON ............ 693 



STARVING FLAT-WORMS .......... 693 



From The School Science Review. 



"LIVING BACKWARDS" .......... 693 



From The School Science Review. 



THE EFFECT OF THE PITUITARY GLAND UPON GROWTH .... 696 

 From Sir Edward Sharpey Schafer's The Endocrine Orgam (Longmans, 

 Green & Co.). 



CASE OF MYXCEDEMA .......... 696 



By permission of the Editor of the Practitioner. 



REJUVENATING A RAT .......... 697 



Reproduced from Steinach's Verjiingung. 



"THE ABUNDANCE OF LIFE" ......... 704 



From Animal Life by the Sea-ihore (Country Life). 



A GROUP OF DIATOM SHIELDS . . . . . . . . 704 



Photo: J. J. Ward. 



A COLLECTION OF DRAGON-FLIES OF THE ORDER ODONATA, WITH THEIR 

 BEAUTIFUL GAUZE-LIKE WINGS ........ 705 



Reproduced from the Smithsonian Report, 1919. 



A GLIMPSE OF THE VARIETY OF LIFE (Coloured Illustration) . . . 706 

 Reproduced from the Smithsonian Report, 1919. 



ANOTHER ILLUSTRATION OF "THE ABUNDANCE OF LIFE" . . . 708 

 Reproduced from the Smithsonian Report, 1919. 



THE BORING PURPLE SEA-URCHIN, Strongylocentratus lividus, IN A 



ROCK POOL, BUNDORAN ......... 709 



Photo: W. A. Green. 



JOHN DALTON (1766-1844) ..... ' . . . . 716 

 Photo: Rischgitz Collection. 



PROFESSOR FREDERICK SODDY ONE OF THE MOST BRILLIANT OF PRES- 

 ENT-DAY CHEMISTS ... . . . . . . . . 716 



Photo: Russell, London. 



MME. SKLODOWSKI CURIE ......... 716 



Photo: Henri Manuel. 



