kn 

26 R. COLLETT. No 
The young of the fourth litter were at that time quite 
small, or still not born. Most of the females of the original 
stock (of which, as previously mentioned there were not very 
many individuals left), were either in young, or had milk in 
their teats. In some the embryos were so small that they 
were but in the very first stage of development. 
The litters follow each other so quickly that occasionally åa 
set of young is produced in å nest, which the young of the 
previous litter have not yet forsaken. Thus (on the l4th August) 
I found å nest (lying under å juniper bush in the highest por- 
tions of the spruce forest), containing 8 large yourg ones of the 
third litter; several of these could not obtain a place in the 
nest itself, but lived at the side of it. There lay, besides, half 
hidden in the straws under those that were in the nest, 6 naked 
new-born brothers and sisters of the fourth set. 
The Nest. Most of these nests were situated on the ex- 
posed and barren heights, well hidden in the tufts of heather 
and lichens (Cetrariae, Cladoniae &c.), or between stones, there- 
fore in their normal home; while, in parts, there lay many nests 
lower down, in the highest stretches of the spruce forests, amongst 
the low brushwood (Juniperus and Betula nana), or, as was often 
the case, in the rotten stumps of trees. 
They were invariably composed of fine straws which were 
but loosely laid together. These were gathered while fresh, 
but dried quickly in the nest. 
The number of young in å litter appears to be greatest in 
the middle of summer or in the second litter, and, as å rule, it 
is then 8 or more. In the third litters which I examined in 
August, the numbers were most often 6 or 5, occasionally 7 or 
8, and on one occasion 101. 
1 Rathke states (Neueste Schriften der Naturf. Gesellsch. Danzig, B. 
II, H. 4, p. 2, Danzig 1842), that during the prolific year in Nam- 
dalen, Trondhjem Stift, in August 1839, he found one female with 
11 embryos. 
