LIXXEAX SOCIETY OF LOXDON. 47 



death of Leuckart in 1S9S, to succeed to the cliair of his old 

 master in Leipzig. 



Clmn's gi-adiiatioii thesis (1878) dealt with the nervous and 

 muscular sy.stems of tlie Cteiiophora, aud was the first of a long 

 series of memoirs, which have become classical, on these and otiier 

 organisms of the marine plankton. The first of the well-known 

 mouographs, issued by the Zoological Station at Xaples, was 

 Chun's volume on the Ctenophora (1880), exquisitely idustrated 

 by his own pencil. It was in this work that he first called atten- 

 tion to a remarkable phenomenon, which he later discussed at 

 greater length (1892) under the name of "Dissogoiiie." Briefly 

 stated, this consists in the occurrence, in certain Ctenophores, of 

 two periods of sexual maturity in the life in the same individual, 

 the one in a larval stage, the second after the assumption of adult 

 characters. These two periods are separated by an interval, during 

 which the genital organs return to a more embrj'onio condition, 

 while the organism continues its metamorphosis. 



In 1888 Chun was associated with Leuekarr in founding the 

 ' Bibliotheca Zoologica' (afterwards ' Zoologica '), perhaps the most 

 lavishly illustrated of all zoological periodicals, of which he after- 

 wards became sole editor. Xotable among his own contributions 

 to this journal are a series of memoirs on the bionomics of pelagic 

 organisms, which appeared under the general title of " Atlantis.^' 

 In tfiese he discussed, among other subjects, the phosphorescent 

 organs and the modified eyes of certain bathypelagic Crustacea, 

 and showed how the structure of the eyes was specially adapted 

 for vision in a dim light. 



In 1898-99 Chun was leader of the German Deep-Sea Expe- 

 dition in the ' Yaldivia,' of which he has given a most interesting 

 account in liis book ' Aus den Tiefen des Weltmeeres ' (1st edn. 

 1902, 2nd edn. 1906). The scientific reports of this expedition, 

 which have been in process of publication under his editorsliip, 

 form a statel}- series of volumes. 



Chun's influence as a teacher is strikingrly commemorated in the 

 'Festschrift,' dedicated to him by his pupils on his sixtieth birth- 

 day and published as a volume of ' Zoologica.' The list of 

 contributors includes many of the most distinguished among the 

 younger zoologists of Grerman}^ aud the variet)^ of the subjects 

 dealt with is evidence of their teacher's interest in widely diverse 

 branches of the subject. 



Chun was elected a Foreign Member of the Linnean Society in 

 1904. He was a foreign member of the • Challenger' Society and 

 a corresponding member of the Zoological Societv of London. 



[W. T. Calman.] 



PetilR Ewixg was born at Kinross on 13th July, 18^9, but passed 

 the greater part of his life in Glasgow; from his early youth he 

 was an enthusiastic botanist, giving all his available leisure from 

 business to the collection of plants. Specially attracted to the 

 study of Alpine plants, he stated in 1911 that he had stood on 



