26 



THE -NATURAL niSTOET RETIEW. 



expose the fallaciousness of the principles upon which that work was 

 based. Dr. v. Siebold has done much and well to reduce the number 

 of Grerman freshwater-fishes. We recommend a glance over the 

 synonymy of the Dace (Squalius leuciscus) p. 203, to those whose 

 tendencies carry them the other way — our author may have gone too 

 far in a few cases. Thus, for instance, nobody who has seen our 

 Chub and its representative of the Continent, will agree with him, 

 that both are of the same species. But there is no fear that other 

 Ichthyologists will allow such questions as these to remain unsettled 

 for long. 



Dr. V. Siebold gives detailed descriptions of those species only 

 which are not perfectly known, whilst the commoner kinds, like the 

 Perch, Pike, etc. are sufficiently characterized in a short diagnosis. 

 His method of examining and describing a fish does not difi'er from 

 that of previous writers, but whatever species is referred to, the 

 account given of it will be found evidently to have been drawn from 

 the author's own original researches, and shows that he has lost no 

 opportunity of thoroughly acquainting himself with his subject. The 

 history of each species is given as completely as possible. Oar author 

 fairly acknowledges where observations previously made, are only 

 confirmed by him, and details the reasons which induce him to enter- 

 tain different views from his predecessors. Even where he does not 

 add any new fact, as for instance in the history of the Eel, his ac- 

 count Avill be read with ]3leasure for its perspicuity, and for the 

 honesty with which he confesses where his own knowledge is incom- 

 plete. 



No other Ichthyological work has dealt in an equally prominent 

 manner with two facts which, if only one half of the observations 

 relating to them shall turn out correct, are of the greatest import- 

 ance in distinguishing the different species, viz, liyhridism, and 

 sterility. The author gives it as his opinion that hybridism is by no 

 means of rare occurrence among fishes, although the cases which 

 he considers as more or less established, belong to one family only, 

 that of the Cyprinoids. They are five in number : 



Hybrid between 



1. Carpio kollarii, Heck. } Cyprinus carpio, K and 



^ i Carassius vulgaris JNilss. 



y. Abramis leuckartii, Ileck. \ Abrauiis, sp : 



, iicciv. J Leuciscus, sp ? 



( Abramis sp ? 

 3. Abramis abramo-rutilus, Holaudre-! Scardinius erythroph- 



(. thalmus, L. 



