MR. A. H. GREEN ON THE BEAVER. 3G3 



grown ; and even then it has not the embonpoint of an elderly 

 beaver. 



I liave read tlmt the beaver breeds at any time during the year ; 

 but this cannot be, or all the kittens that are trapped in the fall 

 would not be of the same size. It produces from three to four at a 

 birth. The teats are placed between the fore legs. The young 

 (called kittens) whimper like young puppies when suckling, even 

 when two months old. The females prefer deep sedgy lakes to 

 bring their young up in, and they feed on grass about that time 

 of the year (July or August). They feed on willow about April, 

 May, and June. I cannot say whether they are born blind or not, 

 but suspect so. They are very fond of water-lilies {Nuphar advena, 

 Ait.) in the spring. It is with me a matter of uncertainty whether 

 the female litters in a house, under the ground, or in the dry 

 sedges ; but I should think, under ground or in the houses. In the 

 autumn more females are caught than males. Trapping com- 

 mences in September and continues to May ; after that the trap- 

 pers leave them alone, so that I do not know much about their 

 doings in the summer. 



They begin to build their dams about July or August, as soon 

 as the summer floods begin to subside. For this purpose they 

 generally choose a bend in the stream, with high and clayey banks, 

 and commence by felling a large tree that will reach across the 

 water ; or they fell a tree on each side of the water so as to meet 

 in the centre. They then float sticks from 6 to 4 feet long down 

 to the dam, and lay them horizontally, filling in the spaces with 

 roots, tufts of grass, leaves, and clay or mud. The branches of 

 the first tree are the perpendicular supports, almost all the re- 

 maining sticks being placed horizontally and crosswise. The last 

 six or eight inches in height is very insecurely constructed, being 

 nothing but mud and leaves. 



The highest dam I ever saw was only about 4 feet 6 inches ; but 

 the generality of them are not above 2 or 3 feet. The action of the 

 water by bringing down mud, gravel, or fallen leaves, strengthens 

 the dam by making a sloping bank against it ; and, the willow sticks 

 of which it is composed sending forth their roots and shoots, the 

 dam in course of time becomes a fixture bound together as strongly 

 as well could be. The winter floods almost invariably destroy the 

 upper part of the dam, which is reconstructed afresh every year. 

 The shape of the dam is almost always semicircular, with the crown 

 of the arch down stream, thus reversing the order of things ; but 



LINN. PEOC. — ZOOLOGY, VOL. X. 25 



