136 



BIOLOGY AND ITS MAKERS 



attracted many young men to the University of Leipsic, is 

 another conspicuous personality in zoological progress. 



This distinguished zoologist, following the lead of Von 

 Siebold, made further modifications. He split Von Siebold's 

 group of Zoophytes into two distinct kinds of radiated animals: 



Fig. 36. — Rudolph Leuckart, 1823-1898. 



the star-fishes, sea-urchins, sea-cucumbers, etc., having a 

 spiny skin, he designated Echinoderma; the jelly-fishes, 

 polyps, coral animals, etc., not possessing a true body cavity, 

 were also united into a natural group, for which he proposed 

 the name Ccelenterata. 



From all these changes there resulted the seven primary 



