MIGRATION. 
401 
gardens of the colonists on the Swan Biver, a locality 
where this species had been hitherto unknown: these 
birds came in myriads, laying the grain crops in one 
night, and spreading devastation around. They withdrew, 
and did not return again for many years. Some years 
ago several Sand Grouse were shot in Holland, they had 
come from Tartary, and were supposed to have lost their 
way. In 1863 we received information from all sides 
that these birds had arrived in large numbers all over 
Central Europe. They sought out favourable places for 
nesting, and bred in the country; by the autumn of the 
same year, however, they were found only very thinly 
distributed; and in the following year but few pairs 
were to be met with at all. Their disappearance was as 
inexplicable as their arrival. 
Many similar instances may be brought forward, 
showing the irregularity of such migrations. Those 
already given, however, will, I think, suffice to demon¬ 
strate the character of the second description of migration. 
The arrival of true birds of passage may be calculated to 
weeks, aye, within days even. The arrival and departure, 
however, of our wandering friends cannot be determined 
any more than their reasons for changing their quarters. 
The third and last class of migration * is much easier 
explained than the above, and for this reason,—because 
it is much more regular in its character. It takes place, 
as I have before remarked, during the entire year, and 
over the whole world. Old bachelors are ever on the 
move; nothing attaches them to any given locality; 
they are ever desirous of change,—seeking, possibly, 
either to enter the sweet bonds of wedlock, or to do 
battle to win the favours of the fair. The great facility 
* German : Streichen, 
8 H 
