THE INSURGENCE OF LIFE 133 



swarming of the Japanese Palolo worm. It invariably 

 takes place about midnight just after flood-tide. At 1 a.m., 

 Akira Izuka relates, the worms ' covered the whole 

 water as with a sheet ' and were thick down to a depth of 

 a fathom. By 2.15 a.m. there was not a single worm to 

 be seen ; the reproductive orgasm was over. The pheno- 

 menon appears to us to be a dramatic instance of the 

 abundance of life, of the crisis-nature of reproduction, and 

 of the precise way in which internal rhythms may be 

 related to external periodicities. 



Dr. Th. Mortensen has called attention to the extra- 

 ordinary fecundity of the starfish Luidia ciliaris, which is 

 well known in British seas. The beautiful red ovaries are 

 arranged in a double series in each arm or ray — 300 in an 

 arm 30 cm. long. As the species is seven-armed a complete 

 female of that size, which is nearly the average, has 2,100 

 ovaries. In one ovary there are at least 300,000 eggs, 

 probably nearer half a million. As the ovaries are smaller 

 towards the tip of the arm, it may be just to take the mean 

 number of eggs per ovary at 100,000, and the number of 

 ovaries may be reduced to 2,000 ; this gives the number 

 of eggs in a grown female at no less than 200 milhons. 

 Yet the larvae are relatively rare and the adults are far 

 from common. ' What a waste of eggs must here take 

 place ! ' 



Professor Lorande Loss Woodruff, of Yale, who has 

 devoted many years to the experimental study of the 

 slipper animalcule [Paramoecium), gives a very interesting 

 account of a five-year pedigreed race. On May 1, 1907, he 

 started with a ' wild ' Paramaecium aurelia, isolated from 

 an aquarium. When it had produced four individuals 

 by division, these were isolated to form the ancestors of 



