Foetal Meinbranes of the American Beaver (Castor cauadensis). 193 



thus broadly separates the great frozen north from the north tem- 

 perate region in these latitudes. It forms in fact a natural barrier 

 to the advance of cultivation and consequently a natural refuge 

 for the beaver. But the same locality is also the resort of the 

 above-mentioned trout which ascend into the numerous lakes that 

 are dotted about the country; it is also the resort of caribou and 

 moose. The beaver has practically no sporting value; but, although 

 its habits clash somewhat with those of the trout, it is incorrect 

 to denounce it as vermin. Vermin are animals which follow culti- 

 vation; not those which recede before it and, in addition, are gifted 

 with a wonderful intelligence. 



The same network of rivers and lakes which is colonised by 

 beavers, also affords suitable conditions for otters. These are to 

 be seen occasionally swimming under the ice wliere it is thin , but 

 they come to the surface at the water-holes wliere the current is 

 too rapid for ice to be formed; their tracks over the snow, leading 

 to inclines down which they slide. are not uncommon. To a certain 

 extent therefore the fish-eating otter, in addition to its aquatic 

 habits and webbed feet, offers a further parallelism to the bark- 

 eating beaver in respect of its subglacial lue during winter. 



2. Collect Ion and p Reservation of material. 



The beavers were trapped under the ice of lakes and off the 

 hanks of a river, the Ri viere Malbaie or Murray river, at a Station 

 called La Roche in Charlevoix county, province of Quebec. An 

 oblong hole was cut through the ice near to a beaver-lodge and 

 the trap , baited with poplar twigs . was fixed on the bottom by a 

 pole; the hole was then covered over with pine-branches which 

 excluded the light. In this way six beavers were caught within 

 a fortnight. At the end of that time the ice began to show signs 

 of breaking up and the snow to soften and melt, so that it became 

 necessary to make the return journey as quickly as possible. 



The six beavers were all females and of these onl}' two were 

 pregnant; one contained four foetus in the right Uterus and none 

 in the left; the other carried two foetus in the right uterus, and 

 again none in the left. The foetus enclosed in their membranes 

 were examined and sketched whilst fresh, and were then preserved 

 in ten per cent formalin. Pieces of the membranes and uterine 

 walls were fixed in Flemming's Solution, in Hill's modification of 



Zool. Jahrb., Suppl. XV (Festschrift für J. W. Speugel Bd. II). 13 



