On the Nervous System of the ChcBtopoda, 311 



banded with crescents of pigment (as in the Trtgla linenta of 

 authors), which likewise forms striking touches here and there 

 on its body. The three free filaments of the pectorals are 

 united by a membrane nearly to the tip, and are used by the 

 fish when creeping on the bottom. The condition of the very 

 young haddock, skulpin, frogfish, ling, rockling, and young 

 flatfishes of various kinds in August (and of this season), all 

 bear out the opinion above expressed, viz. that the young cod 

 which appear off our rocks (and ranging in length from 1 g to 

 If inch in the beginning of June) are not the product of the 

 eggs which abound near the surface of the sea chiefly in 

 April. 



In reference to Prof. Sars's remark about the association of 

 the young fishes with Medusse, I may observe that this asso- 

 ciation in the earlier stages with tlie Ctenophora is followed 

 by different results, for occasionally, on examining the con- 

 tents of the large midwater-net, many Pleurobranchice have 

 young fishes in their stomachs. These young fishes, it is 

 true, are either dead or sickly ; but Fleurohrachia is capable 

 of engulfing somewhat active forms, such as Zoeaj. Whether 

 the products of the reproductive organs of the Medusas are 

 utilized by the larval fishes is still an open question. Their 

 enormous numbers in the sea around them, at all events, is a 

 striking feature. Hydroids, such as Ohelia geniculata, are 

 greedily eaten by young green cod, and the stomachs of the 

 adult common cod contain diverse Coelenterates. 



XXXI. — Histological Investigations upon the Nervous System 

 of the Chcetopoda. ^y Dr. Emil Rohde*. 



Histological investigations upon the nervous system of 

 Polynoe elegans had shown me that the so-called neural 

 canals in the Polychasta were colossal nerve-fibres, the detailed 

 study of which promised important data as to the structure of 

 the nervous system in animals generally. By the munifi- 

 cence of the Berlin Academy of Sciences I was last year 

 enabled to work for several months in the Zoological Station 

 at Naples, and to collect from the Polychteta occurring in the 

 Bay abundant materials for the further prosecution of this 



* Translated by W. S. Dallas, F.L.S., from the ' Sitzungsberichte 

 der k. preussischen Academie der Wissenschafteii,' July 29, 1886, pp. 

 781-786. 



