1907] The Marine Biological Station "and its Work. 109 



of an inch in diameter. The shad's eggs are separate and neither 

 cHng to each other nor float at the surface of the water. They 

 are comparatively large (one-seventh of an inch in diameter) 

 and roll about amongst gravel, etc., in shallow streams and 

 rivers above tidal limits. As Professor Prince's four beautiful 

 drawings of the young alewife or gaspereau (on Plate X) are the 

 first ever executed of these early stages, they are of great scientific 

 value, while the detailed drawings of the scales, etc., are of 

 extreme interest. Professor Prince also furnishes a very readable 

 account of the profound and technical researches of Professor 

 A. B. Macallum, one of the most distinguished scientific men 

 whom Canada has produced. The researches of the brilliant 

 Professor of Physiology in Toronto Universit}^ are better known 

 in England and Germany than in our own country, and London 

 last year honoured Dr. Macallum with the coveted F. R. S. of 

 England. Professor Macallum investigated the "Chemistry of 

 Medusce" for several seasons in the Biological Station and pub- 

 lished his results in the Journal of Physiology, Vol. XXIV. 

 Professor Prince, who edits the present publication, desired a 

 less technical and more popular version of the published paper; 

 but for various reasons, it is understood, that a simplified ac- 

 count could not be prepared by the author in time for the 

 present issue. Professor Prince himself therefore wrote this 

 very fascinating version of Dr. Macallum's paper, minus tech- 

 nicalities, and presented in a revised popular form. The lovely 

 floating medusae or jellyfish, often brilliantly coloured, are 

 generally thought to be composed of delicate, transparent skin 

 and water. There is certainly little solid matter in them. Pro- 

 fessor Owen dried a jellyfish, which weighed two pounds when 

 alive, and found that its weight was barely thirty grains, or 

 about one-five-hundredth of the original weight. Professor 

 Macallum establishes the complex composition of the "jellyfish 

 juice," and the amazing physiological independence and sta- 

 bility of the jellyfish cells. He disproves Professor Loeb's 

 contention that the chemical nature of the surrounding water 

 directly affects either the chemical nature of the medusa or 

 its living movements and functions. Professor Macallum 

 proves that each has its own individual resisting power and a 

 wonderful independence of outside chemical changes, while the 

 cells, composing the medusa's body, have a surprising selective 

 power, and accept or reject the various salts in the surrounding 

 sea-water, as the experiments demonstrated. Nay, more, their 

 chemical constitution appears to be that which must have 

 characterized animals in the primal seas of our planet. May it 

 not be that the serum, the clear part of our own blood, is the 



