152 REPEODUCTION AND GROWTH OF THE PILCHARD. 



G. Pouchet, who is Director of a marine laboratory at Concarneau, 

 on the coast of Brittany, and by Professor Marion, who has a similar 

 laboratory at Marseilles. 



The first publication in which Pouchet mentions the mature egg 

 of the sardine is a note in the Comptes Rendus of the French 

 Academie des Sciences, tome cix, No. 3 (July 15th, 1889). He 

 states there that the sardine de rogue is a young sardine which is 

 not yet full grown, and which has not yet spawned ; while the sardine 

 de derive is alone adult, and alone sometimes contains mature ova. 

 The explanation of these French terms, applied to sardines of 

 different sizes on the French coast, is as follows : — Rogue is the 

 name given by the French fishermen to a preparation of cods' roe 

 which they throw into the water as a bait to attract the sardines. 

 After the bait is thrown overboard a seine is shot round the place, 

 and the sardines thus enclosed. Sardines de rogue are thus sardines 

 caught by means of rogue and seine. Derive, on the other hand, 

 means drift, and sardines de derive are those caught in drift-nets. 



Pouchet proceeds to briefly describe the ripe ova taken from large 

 sardines. He says they measure 1*20 to 1"30 mm. in diameter; 

 that they are transparent, heavier than sea water, and in the latter 

 fall rapidly to the bottom. He says that there is little probability 

 that the fertilized egg would behave differently, although some have 

 supposed that it does. In any case, he says, he and his colleagues 

 have never found this egg at the surface of the sea in the Bay of 

 Concarneau. According to the same paper the vitelline membrane 

 of the sardine's egg is smooth at its outer surface, but on its 

 inner surface presents a reticulation of projecting ridges. The mem- 

 brane consists of two layers, an external very thin and very re- 

 fringent, and an internal thicker layer. The vitellus is granular 

 and filled entirely with clear spheres, and with a single oil -globule 

 of a pinkish colour. The paper concludes by insisting that the 

 irregularity in the condition of the ovaries in the sardines de rogue 

 indicates that the reproduction of the species is not subject to the 

 influence of the seasons, but, like the greater part of the existence 

 of the species, is carried in waters whose temperatures are nearly 

 constant, that is in regions beyond the reach of man. 



It is evident that, apart from the vitelline membrane, Pouchet does 

 not differ from me as to the structure of the ripe egg of the pilchard ; 

 and as he has never seen the fertilized egg, it is somewhat hazardous 

 on his part to argue that it does not float. The note above cited 

 was published subsequently both to my paper and Raffaele's, so that it 

 must be presumed that Pouchet attaches little weight to our evidence. 



In his Keport on the Concarneau Laboratory for 1889 presented to 

 the French Minister of Public Instruction, and reprinted in the 



