198 



Alcune osservazioni sullo Strongylocentr otus lividus che 

 nelle line generali si accordaiio con quelle di Driesch sull' Echinus 

 e sullo Sphaer echinus ed alcune altre affatto fraramentarie, sulla 

 Ciona intestinalis e su di una Sagitta saranno riferite nel 

 lavoro completo. 



Nachdruck verboten. 



The Pronephros of Lepidosteus osseus. 



By J. Beabd, D. Sei., 

 university Lecturer on Comparative Embryology, Edinburgh. 



In two recent numbers ^) of the "Zoologischer Anzeiger" Dr. H. F, E. 

 JuNGERSEN has fumished interesting descriptions of the pronephros of 

 Acipenser sturio and of Amia calva. In both of these papers the 

 author naturally refers to the current accounts of the same organ in 

 Lepidosteus due to Balfour and Parker and to myself. He rightly 

 regards neither of these as satisfactory. In the more recent of his 

 communications (p. 251 — 252) Jungersen discusses the possibiHty of 

 a close resemblance between the pronephros of Amia and that of Le- 

 pidosteus — a resemblance depending on the validity, with shght 

 differences of interpretation, of the account given by Balfour and 

 Parker. But no decision is arrived at in consequence of the discre- 

 pancies between their results and mine. 



Soon after the appearance of Semon's work in 1891 I recognised, 

 on re-examination of my preparations, that a fundamental error lay in 

 the earlier account of my preliminary paper ^). The inner funnels had 

 been overlooked in the first instance — a mistake exactly comparable 

 to one made by Jungersen in a previous paper in which the prone- 

 phros of Acipenser was referred to. 



My newer results have been kept back for various reasons, i. e. 

 the non-completion of the necessary drawings, and the pressure of 

 other duties etc. In consequence of Jungersen's appeal (p. 252), a 

 brief outline is now published, to be followed by a fuller account sub- 

 sequently. 



1) JuNGEBSEN, H. F. E., Die Embryonalniere des Störs (Acipenser 

 sturio), in Zool. Anz., 1893, Nos. 435, 436, and Die Embryonalniere von 

 Amia calva, in Zool. Anz., 1894, No. 451. 



2) Proc. Koy. Soc. Lend, 1889, p. 115. 



