Anton Schneider (1831 - 1890) was a famous German 

 zoologist, who in a work on the development of the mollusc 

 Phyllirhoe bucephalumS? warmly mentioned "the repeated 

 friendly directions" which he received from Krohn not only 

 during the observations taken for that work, hit also 

 throughout the time of their presence together in Messina 

 in the spring of 1858. Significantly later, in 1867, Krohn 

 met with Schneider in Nice; Schneider was interested there 

 in larvae of any polychaetes which were covered with peculiar 

 porous membrane. Schneider found that these larvae were well 

 known to Krohn. In addition, as Schneider wrote, "Krohn, 

 with his characteristic generosity, gave me the relevant 

 pages of his journal that I might use the information 

 contained in it at my discretion, expressing the hope that 

 I could trace the further development of these larvae" (p. 498, 

 footnote) . 



Other works reveal that Krohn did not intend to publish 

 his materials on the development of this polychaete, and 

 agreed that Schneider would do this himself. Schneider wrote 

 the work, its first part (description of the early stages) 

 containing his own materials, and the second the results of 

 Krohn 's observations on subsequent development. The work was 

 published under the names of both authors, Krohn 's name in 

 first place. 38 



Helping to increase his material, Krohn showed at the same 

 time extreme punctiliousness in relation to the strange data. 

 This is illustrated by Krohn' s following remark on one of the 

 early works about the structure of the nervous system in the 

 echinoderms,39 as he sought to eliminating all shades of 

 suspicion of incorrectness in relation to the published data 

 of other investigators: 



37. A. Schneider, "Uber die Entwickelung der PHYLLIRHOE 

 BUCEPHALUM," ARCH. ANAT . , PHYSIOL. (1859), 

 pp. 35 - 37. 



38. A. Krohn und A. Schneider, "Uber Annelidlarven mit porosen 

 Hullen," ARCH. ANAT., PHYSIOL. (1867), pp. 498 - 508. 



39. A. Krohn, "Uber die Anordnung des Nervensystems der 

 Echiniden und Holothurien im Allgemeinen," ARCH. ANAT . , 

 PHYSIOL. (1841), pp. 1 - 13. 



564 



