IVi PEOCEEDIXGS 01" THE 



iudi^-idiials witli races, and overloadiiig witli practically useless 

 matter our floras aud faunas. I say, faunas as well as floras ; for 

 similar circumstances appear to attend tlie production of hybrids 

 in a wild state in tlie animal as in the vegetable kingdom. Tliey 

 are at least weU exemplified, in the case of fishes, in Professor C. 

 Th. E. A . Siebold's elaborate monogi'aph of ' Central European 

 Freshwater Fishes,' to Avhich Dr. Sclater has refen-ed me — not 

 unirequent, but usually ahnost isolated, specimens of the hybrid 

 caught where the parents are in shoals, and diflerences so great 

 between the individuals of the same origin as to have caused 

 them to be classed sometimes with the one, sometimes with the 

 other parent. The evidences of hybridity adduced by the author 

 in each instance appear to be convincing ; and, so far as I may be 

 allowed to pronounce an opinion on what is out of my special 

 department, the work gives proof of gi-eat pains and labour 

 successfully bestowed upon collecting and methodizing all that 

 could be learnt on the subject chosen, but shows at the same time 

 that ichthyologists are determined not to be outdone by botanists 

 in the reckless splitting of genera. In four of the five cases given of 

 undoubted hybrids, the two parents are placed in diflerent genera ; 

 in three of these, the ofi'spring is referred to a third ; and in two 

 out of these three, the third genus is a new one, created for the hy- 

 brid alone. If this be correct, if a genus may be less than a 

 species, the question naturally occiu-s, "What does a genus mean, 

 and where is its use ? 



As to the direction in which future researches on hybridism are 

 likely to be the most useful, it does not appear that any further 

 evidence is required in support of Darwin's general laws and ex- 

 ceptions, as confinned by Xaudin. No number of cases of sterility 

 in hybrids will disprove the well-established ones of exceptional 

 fertility. But Xaudin's hypothesis of the intermixture and sub- 

 sequent disjunction of parental essences opens out a new field of 

 research, requiring for its confirmation or refutation numerous 

 varied and careful experiments, which may ultimately give us 

 some further insight into the hitherto concealed mysteries of 

 fecundation. Practically also, much is to be done in the observa- 

 tion of plants in a wild state. Hybrids in our cold damp northern 

 climates always appear to me much less frequent than in the 

 south, for the same reasons, perhaps, that the proportion of per- 

 ennials to annuals, and of propagation by offset to propagation 

 by seed, is greater in the north than in the south. Is that the 

 case ? Is the confusion in the delineation of our willows, for in- 



