SCIENTIFIC NOTES AND OBSERVATIONS. 141 



Hybridism. — Connected witli the subject of specific formation is 

 the subject of hybridism. From the point of view of the systematist 

 the different species of Smerinthns are generically divisible ; that is, 

 they offer characters which in other moths are hekl to be of generic 

 vahie, and, so far as we know, ai*e then usually a barrier to hybridism. 

 Not so here, and this is an argument for the Bom])ycine (Saturnian) 

 origin of the Family Sphhtgidac. The type of Siaerint/iHH, Lutr. is 

 seemingly popnli. This moth is structurally different from ocellafus, 

 and again from tiliae. In America, Paonias, Hb., affords another 

 ocellated Smerinthoid type. Hybridism must occasionally occur under 

 natural conditions. The correct view seems to be that hybrids do not 

 harden into species, but gradually die out or are absorbed. Species 

 have not originated by hybridism. The forces which, over longer 

 periods, have moulded the specific type cannot be replaced by a single 

 violent action rendered possible by the hidden or reminiscent affinities 

 of the cells. The systematist has nothing to do with hybridity. The 

 impossibility or the non-occurrence of hybridism in any one case 

 forms no part of his generic diagnosis. He is concerned with certain 

 external structural features, the various visible modifications of which 

 form the characters on which he founds his groupings. He may at a 

 later scientific epoch be corrected by the morphologist ; at the present 

 time he cannot be called upon to draw in a genus Ijecause one of its 

 members is fertile with a species of another genus upon an isolated 

 occasion. Hybrids between members of distinct genera must be care- 

 fully examined to ascertain the relative fixity of structural characters 

 — their ultimate value for purposes of classification. No secpience in 

 point of value is yet established for generic characters in the 

 Lepidoptera. The systematist uses modifications taken from the entire 

 periphery upon which to base his groups. Characters which in the 

 Lepidoptera seem stable — such as the hairiness of the compound eye — 

 seem in other orders, e.g. Diptera, variable. The frontal horn seems 

 to 1)0 a constant character in the moths ; in Coleoptera it is sexual or 

 variable. The gradual fitting of our nomenclature, which is artificial, 

 to natural objects is a process involving time and labour, and will 

 become more intimate than it is to-day. Always are our systems 

 improving, reflecting more accurately the facts. It is not yet two 

 hundred years since Linnaeus was with us in the flesh. It cannot be 

 denied that we have occupied much fresh territory since his day. 

 Nomenclature, the organic expression of i)hysiological fact, will follow 

 its own development, unim})eded by momentary and individual 

 expressions of impatience, dependent alone on the conditions of the 

 human mind which gave it birth. — A. K. Grote, A.M., Bremen. — [We 

 should like to know in what way S. popnli is " structurally different from 

 ocellatus and tiliae,'" i.e., sufficiently different for generic characters, and 

 also in what respects the genus Paonias differs from the genus 

 Smeriuthas ? — Eu.] 



^URRENT NOTES. 



I'he liev. W. F. Johnson records (E.M.M., Feb.) the capture last 

 year, at Mullinure in the North o( Irt'land of two specimens of Ilcpiahm 

 humuli. According to Mr. Johnson, 3Ir. Barrett's caiituic of this moth 

 in Galway seems to be the only other record of its occurrence in Ireland. 



