40 On Lanius excubitor and Lanius major. 



2. Sometimes, however, among the normally coloured 

 young are produced a few having the basal spot on the 

 secondaries either imperfect or wholly wanting, and every 

 conceivable transition between this and the typical form. 



3. Such individuals, with the basal spot on the secon- 

 daries either imperfect or wanting, become more common 

 throughout the Arctic region ; and in Northern Asia these 

 are the normal {L. excubitor, forma major), while the double- 

 spotted variety occurs comparatively seldom. 



4. At the same time that the basal spot on the secondaries 

 is either in part or wholly suppressed, some individuals have 

 a tendency to exhibit a buff colouring on the rump and tail- 

 coverts {L. excubitor, forma mollis), also more distinct and 

 permanent vermiculations across the abdomen, till in North 

 America (L. excubitor, forma borealis) this character becomes 

 normal. 



5. Moreover the typical L. excubitor sometimes, too, pro- 

 duces individuals having the basal spot on the secondaries 

 larger than in the typical form, while at the same time the 

 white colour becomes more expanded on the feathers of the 

 rump and the outermost rectrices (L. excubitor, forma 

 homey eri) . 



6. Such individuals, occasionally produced also in Northern 

 Europe, become more frequent further south, till in South- 

 eastern Europe they are normal. 



7. This tendency to develop the white colour increases 

 with the distance east, till the most pronounced form 

 [L. excubitor, forma leucopterus) meets in South Siberia 

 the northern and darker forms of the species mentioned 

 above. 



8. Assuming the observations from these districts to 

 be trustworthy, the last form keeps throughout that region 

 (Seebohm, ' Siberia in Asia/ p. 243) distinctly different from 

 the others. 



Christiania, SOth Nov., 1885. 



