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. eoccubitor, 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, f Siberia in Asia/ p. 243) distinctly different from 
the others. 
Christiania, 30th Nov., 1885. 
