XVI A BIOGRAPHICAL NOTICE OF 



In treating of Dr. Horn's connection with the journal " Entomo- 

 logical News" we have mentioned a number of short papers which 

 he pulilished therein concerned with variation in Coleoptera. From 

 the most important of these, published in February, 1892, dealing 

 with Cicindela ^^' we extract : " Recently the subject of variation in 

 coloration has been discussed before the Society of American Natu- 

 ralists with the view of eliciting an expression as to whether color 

 variation proceeded in a regular course, or was hap-hazard and acci- 

 dental. My observations have been that variation proceeds in reg- 

 ular lines, easily demonstrable with sufficient material, produced by 

 external influences which are at present but partly understood. 

 There is probably no branch of zoology better fitted to illustrate 

 this point than Entomology, from the abundance of species and the 

 frequent occurrence of genera with large numbers of species in 

 which a greater or less similarity of marking is observable." After 

 showing the various lines along which color variations on the elytra 

 exist, illustrated by a plate, he refrains, with his usual caution, from 

 any speculations suggested by these facts, as follows : " In view of 

 all the facts here presented the question might be asked, why do 

 some species vary while others do not? While this matter is worthy 

 of some thought, it is not possible to give a satisfactory answer. 

 Some species doubtless vary from climatic causes. A notable in- 

 stance will be seen in hcemorrhagica, which extends from San Diego 

 and Yuma in California northwards to the headwaters of the Yel- 

 lowstone, passing through about all possible varieties of climate and 

 habitat, from sea-coast to mountain. On the other hand hirticollis 

 occurs from Hudson's Bay to Arizona without variation, and the 

 specimens of lepida from the New Jersey shore are not separable 

 from those found in Nebraska. It seems hardly possible to make 

 any generalizations on the subject. Doubtless the coast species vary 

 to a greater extent taking them collectively than do the inland spe- 

 cies, but it is impossible to go further in speculation as too many 

 exceptions arise on all sides." Doubtless the conclusion which most 

 appealed to him was that which he expressed in his closing sentence : 

 " Should the method of thought which gave rise to the preceding 

 remarks produce in some others thoughts as to the possibilities of 

 variation, not only in color, but almost equally in foi'm and sculp- 

 ture there would be less synonymy to be corrected and a more ti'uly 

 scientific basis established for species." This paper has been re- 

 printed in part by Prof. Cope, in his ' Primary Factors of Organic 



